diff --git a/API.md b/API.md
index 8fbca7d..56bdc4d 100644
--- a/API.md
+++ b/API.md
@@ -21,26 +21,26 @@
 
 
 - `laptop.os_get(pos)` - Get an OS object. Usefull in on_construct or on_punch to initialize or do anything with OS
-  Needed in on_receive_fields to be able to call os:receive_fields(fields, sender) for interactive apps
+  Needed in on_receive_fields to be able to call mtos:receive_fields(fields, sender) for interactive apps
 - `laptop.after_place_node` / `laptop.after_dig_node` - (optional) can be used directly for node definition. Move laptop apps data to ItemStack if digged and restored back if placed again. So you can take along your laptop. Note: you need to set `stack_max = 1` because the data can be stored per stack only, not per item.
 
 
 ## Operating system calls
 Usable from node functions, from apps or outsite
 
-`local os = laptop.os_get(pos)` - Get the Operating system object. pos is the node position
+`local mtos = laptop.os_get(pos)` - Get the Operating system object. pos is the node position
 
-- `os:power_on(new_node_name)` - Activate the app "launcher" and if given swap node to new_node_name
-- `os:resume(new_node_name)` - Restore the last running app after power_off. if given swap node to new_node_name
-- `os:power_off(new_node_name)` - Remove the formspec and if given swap node to new_node_name
-- `os:swap_node(new_node_name)`- Swap the node only without any changes on OS
-- `os:set_infotext(infotext)` - Set the mouseover infotext for laptop node
-- `os:save()` - Store all app-data to nodemeta. Called mostly internally so no explicit call necessary
-- `os:get_app(appname)`- Get the app instance
-- `os:set_app(appname)` - Start/Enable/navigate to appname. If no appname given the launcher is called
-- `os:receive_fields(fields, sender)` - Should be called from node.on_receive_fields to get the apps interactive
-- `os:get_theme(theme)`- Get theme data current or requested (theme parameter is optional)
-- `os:set_theme(theme)`- Activate theme
+- `mtos:power_on(new_node_name)` - Activate the app "launcher" and if given swap node to new_node_name
+- `mtos:resume(new_node_name)` - Restore the last running app after power_off. if given swap node to new_node_name
+- `mtos:power_off(new_node_name)` - Remove the formspec and if given swap node to new_node_name
+- `mtos:swap_node(new_node_name)`- Swap the node only without any changes on OS
+- `mtos:set_infotext(infotext)` - Set the mouseover infotext for laptop node
+- `mtos:save()` - Store all app-data to nodemeta. Called mostly internally so no explicit call necessary
+- `mtos:get_app(appname)`- Get the app instance
+- `mtos:set_app(appname)` - Start/Enable/navigate to appname. If no appname given the launcher is called
+- `mtos:receive_fields(fields, sender)` - Should be called from node.on_receive_fields to get the apps interactive
+- `mtos:get_theme(theme)`- Get theme data current or requested (theme parameter is optional)
+- `mtos:set_theme(theme)`- Activate theme
 
 
 ## App Definition
@@ -50,14 +50,14 @@ Usable from node functions, from apps or outsite
 - `app_info` - Short app info visible in launcher tooltip
 - `fullscreen` - (boolean) Do not add app-background and window buttons
 - `view` - (boolean) The definition is a view. That means the app/view is not visible in launcher
-- `formspec_func(app, os)` - Function, should return the app formspec (mandatory) During definition the "app" and the "os" are available
-- `appwindow_formspec_func(launcher_app, app, os)`- Only custom launcher app: App background / Window decorations and buttons
-- `receive_fields_func(app, os, fields, sender)` Function for input processing. The "app" and the "os" are available inside the call
+- `formspec_func(app, mtos)` - Function, should return the app formspec (mandatory) During definition the "app" and the "mtos" are available
+- `appwindow_formspec_func(launcher_app, app, mtos)`- Only custom launcher app: App background / Window decorations and buttons
+- `receive_fields_func(app, mtos, fields, sender)` Function for input processing. The "app" and the "mtos" are available inside the call
 `laptop.register_view(internal_shortname, { definitiontable })` - add a new app or view
 same as register_app, but the view flag is set. app_name and app_icon not necessary
 
 ## App Object
-`local app = os:get_app(appname)` - Give the app object internal_shortname, connected to given os. Not necessary in formspec_func or receive_fields_func because given trough interface
+`local app = mtos:get_app(appname)` - Give the app object internal_shortname, connected to given mtos. Not necessary in formspec_func or receive_fields_func because given trough interface
 - `data = app:get_storage_ref(appname)` - Returns a "persitant" data table from nodemeta (=hdd). The data in this table is not lost between formspec_func, receive_fields_func, apps-switch or on/off. Appname is optional to get data from other app
 - `data = app:get_cloud_storage_ref(appname)` - Returns a persistant table from modmeta (=internet)
 - `app:back_app() - Go back to previous app/view
@@ -72,3 +72,9 @@ Definitiontable:
 - `exit_button` Exit button image
 - `major_button` Major (highlighted) button image
 - `minor_button` Minor button image
+- `textcolor` Default text color for buttons and labels. For buttons the major_textcolor and minor_textcolor supported
+
+## Theme methods
+`function laptop.get_theme(theme_name)`
+- `theme:get_button(area, prefix, code, text)` get a themed [prefix]_button in area 'x,y;w,h' with code an text
+- `theme:get_label(pos, text)` get a themed label text starting at pos 'x,y'
diff --git a/apps/calculator_app.lua b/apps/calculator_app.lua
new file mode 100644
index 0000000..4bb9585
--- /dev/null
+++ b/apps/calculator_app.lua
@@ -0,0 +1,133 @@
+laptop.register_app("calculator", {
+	app_name = "Calculator",
+	app_icon = "laptop_calculator.png",
+	app_info = "Calculate things",
+	formspec_func = function(app, mtos)
+		local data = app:get_storage_ref()
+
+		if not data.tab then
+			data.tab = {}
+		end
+		if not data.tab[1] then
+			table.insert(data.tab, {})
+		end
+
+		local formspec = "tablecolumns[" ..
+			"text,align=right,padding=1.5,width=10;".. -- first value
+			"text,align=right,padding=1.5;".. -- operator
+			"text,align=right,padding=1.5,width=10]".. -- last value
+			"table[3.9,0.8;7,2;tab;"
+
+		for idx,entry in ipairs(data.tab) do
+			if idx > 1 then
+				formspec = formspec..','
+			end
+			formspec = formspec..(entry.var1 or "")..","..(entry.operator or "")..","..(entry.var2 or "0")
+		end
+
+		formspec = formspec .. ";"..#data.tab.."]"..
+				mtos.theme:get_button('4,3;1,1', "minor", 'number', '1') ..
+				mtos.theme:get_button('5,3;1,1', "minor", 'number', '2') ..
+				mtos.theme:get_button('6,3;1,1', "minor", 'number', '3') ..
+				mtos.theme:get_button('4,4;1,1', "minor", 'number', '4') ..
+				mtos.theme:get_button('5,4;1,1', "minor", 'number', '5') ..
+				mtos.theme:get_button('6,4;1,1', "minor", 'number', '6') ..
+				mtos.theme:get_button('4,5;1,1', "minor", 'number', '7') ..
+				mtos.theme:get_button('5,5;1,1', "minor", 'number', '8') ..
+				mtos.theme:get_button('6,5;1,1', "minor", 'number', '9') ..
+				mtos.theme:get_button('4,6;1,1', "minor", 'number', '0') ..
+				mtos.theme:get_button('5,6;1,1', "minor", 'number', '.') ..
+
+				mtos.theme:get_button('8,3;1,1', "minor", 'operator', '+') ..
+				mtos.theme:get_button('8,4;1,1', "minor", 'operator', '-') ..
+				mtos.theme:get_button('8,5;1,1', "minor", 'operator', '/') ..
+				mtos.theme:get_button('8,6;1,1', "minor", 'operator', '*') ..
+				mtos.theme:get_button('9,6;2,1', "minor", 'operator', '=') ..
+
+				mtos.theme:get_button('9,3;2,1', "minor", 'del_char', 'DEL-1') ..
+				mtos.theme:get_button('9,4;2,1', "minor", 'del_line', 'DEL-L') ..
+				mtos.theme:get_button('9,5;2,1', "minor", 'del_all', 'DEL-A')
+		return formspec
+	end,
+
+	receive_fields_func = function(app, mtos, fields, sender)
+		local data = app:get_storage_ref()
+		local entry = data.tab[#data.tab]
+
+		if fields.number then
+			-- simple number entry
+			entry.var2 = (entry.var2 or "")..minetest.strip_colors(fields.number)
+		elseif fields.del_char then
+			-- delete char
+			if entry.var2 and entry.var2 ~= "" then
+				-- remove char from current number
+				entry.var2 = entry.var2:sub(1, -2)
+				if entry.var2 == "" then
+					entry.var2 = nil
+				end
+			else
+				-- get previous number
+				if #data.tab > 1 then
+					-- go back to previous line if exists
+					table.remove(data.tab, #data.tab)
+				else
+					-- get from left site if first entry
+					entry.var2 = entry.var1
+					entry.operator = nil
+					entry.var1 = nil
+				end
+			end
+		elseif fields.del_line then
+			-- just delete full number if exists
+			if entry.var2 and entry.var2 ~= "" then
+				entry.var2 = nil
+			else
+				-- go back to previous line and delete the full number if exists
+				table.remove(data.tab, #data.tab)
+				if #data.tab > 0 then
+					entry = data.tab[#data.tab]
+					entry.var2 = nil
+				end
+			end
+		elseif fields.del_all then
+			data.tab = nil
+		elseif fields.operator then
+			fields.operator = minetest.strip_colors(fields.operator)
+			local entry = data.tab[#data.tab]
+			-- no previous operator
+			if not entry.operator then
+				if fields.operator == '=' then
+					table.insert(data.tab, {}) -- add empty line
+				elseif entry.var2 and entry.var2 ~= "" then
+					-- move to the left
+					entry.var1 = entry.var2
+					entry.operator = fields.operator
+					entry.var2 = nil
+				end
+
+			-- process previous operator
+			else
+				local result
+				if entry.operator == '+' then
+					result = tonumber(entry.var1) + tonumber(entry.var2)
+				elseif entry.operator == '-' then
+					result = tonumber(entry.var1) - tonumber(entry.var2)
+				elseif entry.operator == '/' then
+					result = tonumber(entry.var1) / tonumber(entry.var2)
+				elseif entry.operator == '*' then
+					result = tonumber(entry.var1) * tonumber(entry.var2)
+				elseif entry.operator == '=' then
+					result = tonumber(entry.var2)
+				end
+				if not result then
+					result = 0
+				end
+				if fields.operator == '=' then
+					table.insert(data.tab, {var2 = tostring(result)})
+				else
+					table.insert(data.tab, {var1 = tostring(result), operator = fields.operator})
+				end
+			end
+		end
+	end
+})
diff --git a/apps/launcher_app.lua b/apps/launcher_app.lua
index ef47074..230fad7 100644
--- a/apps/launcher_app.lua
+++ b/apps/launcher_app.lua
@@ -2,13 +2,13 @@
 laptop.register_app("launcher", {
 --	app_name = "Main launcher", -- not in launcher list
 	fullscreen = true,
-	formspec_func = function(launcher_app, os)
+	formspec_func = function(launcher_app, mtos)
 		local c_row_count = 4
 
 		local i = 0
 		local out = "size[15,10]"
-		if os.theme.launcher_bg then
-			out = out..'background[15,10;0,0;'..os.theme.launcher_bg..';true]'
+		if mtos.theme.launcher_bg then
+			out = out..'background[15,10;0,0;'..mtos.theme.launcher_bg..';true]'
 		end
 		local appslist_sorted = {}
 		for name, def in pairs(laptop.apps) do
@@ -20,34 +20,35 @@ laptop.register_app("launcher", {
 		for i, e in ipairs(appslist_sorted) do
 			local x = math.floor((i-1) / c_row_count)*2 + 1
 			local y = ((i-1) % c_row_count)*2 + 1
-			out = out .. 'image_button['..x..','..y..';1,1;'..os.theme.app_button..'^'..(e.def.app_icon or 'logo.png')..';'..e.name..';]'..
+			out = out .. 'image_button['..x..','..y..';1,1;'..mtos.theme.app_button..'^'..(e.def.app_icon or 'logo.png')..';'..e.name..';]'..
 						'label['..(x-0.3)..','..(y+1)..';'..e.def.app_name..']'..
 						'tooltip['..e.name..';'..(e.def.app_info or e.name)..']'    --;<bgcolor>;<fontcolor>]'
 		end
+		out = out..mtos.theme:get_button("11,9.8;4,0.7", "major", "os_clock", os.date("%c"))
 		return out
 	end,
-	appwindow_formspec_func = function(launcher_app, app, os)
+	appwindow_formspec_func = function(launcher_app, app, mtos)
 		local formspec = 'size[15,10]'
-		if os.theme.app_bg then
-			formspec = formspec..'background[0,0;15,10;'..os.theme.app_bg..';true]'
+		if mtos.theme.app_bg then
+			formspec = formspec..'background[0,0;15,10;'..mtos.theme.app_bg..';true]'
 		end
-		if #os.appdata.os.stack > 0 then
-			formspec = formspec..'image_button[-0.29,-0.31;1.09,0.61;'..os.theme.back_button..';os_back;<]' --TODO: if stack exists
+		if #mtos.appdata.os.stack > 0 then
+			formspec = formspec..'image_button[-0.29,-0.31;1.09,0.61;'..mtos.theme.back_button..';os_back;<]'
 		end
 		if app.app_info then
-			if #os.appdata.os.stack > 0 then
+			if #mtos.appdata.os.stack > 0 then
 				formspec = formspec.."label[0.8,-0.29;"..app.app_info.."]"
 			else
 				formspec = formspec.."label[-0.1,-0.29;"..app.app_info.."]"
 			end
 		end
-		formspec = formspec..'image_button[14.2,-0.31;1.09,0.61;'..os.theme.exit_button..';os_exit;X]'
+		formspec = formspec..'image_button[14.2,-0.31;1.09,0.61;'..mtos.theme.exit_button..';os_exit;X]'
 		return formspec
 	end,
-	receive_fields_func = function(launcher_app, os, fields, sender)
+	receive_fields_func = function(launcher_app, mtos, fields, sender)
 		for name, descr in pairs(fields) do
 			if laptop.apps[name] then
-				os:set_app(name)
+				mtos:set_app(name)
 				break
 			end
 		end
diff --git a/apps/launcher_settings_app.lua b/apps/launcher_settings_app.lua
index f0ebfb0..1a8d03d 100644
--- a/apps/launcher_settings_app.lua
+++ b/apps/launcher_settings_app.lua
@@ -12,15 +12,15 @@ laptop.register_app("launcher_settings", {
 	app_icon = "laptop_setting_wrench.png",
 	app_info = "Change the computer's settings.",
 
-	formspec_func = function(app, os)
+	formspec_func = function(app, mtos)
 		local settings_data = app:get_storage_ref()
 
 		-- Change background setting
-		local current_theme_name = settings_data.selected_theme or os:get_theme().name or "default"
-		local current_theme = os:get_theme(current_theme_name)
+		local current_theme_name = settings_data.selected_theme or mtos:get_theme().name or "default"
+		local current_theme = mtos:get_theme(current_theme_name)
 		local current_idx
 
-		local formspec = "label[0,0.5;Select theme]"
+		local formspec = mtos.theme:get_label('0,0.5', "Select theme")
 
 		local formspec = formspec.."textlist[0,1;5,2;sel_theme;"
 		for i, theme in ipairs(themes_tab) do
@@ -41,12 +41,12 @@ laptop.register_app("launcher_settings", {
 			formspec = formspec.."image[5.5,1;5,3.75;"..current_theme.launcher_bg.."]"
 		end
 
-		formspec = formspec..'image_button[-0.14,3;3,1;'..current_theme.major_button..';theme_apply;Apply]'
+		formspec = formspec .. mtos.theme:get_button('0,3.2;2.5,0.6', 'major', 'theme_apply', 'Apply', 'Apply theme')
 
 		return formspec
 	end,
 
-	receive_fields_func = function(app, os, fields, sender)
+	receive_fields_func = function(app, mtos, fields, sender)
 		local settings_data = app:get_storage_ref()
 
 		if fields.sel_theme then
@@ -56,9 +56,8 @@ laptop.register_app("launcher_settings", {
 		end
 
 		if fields.theme_apply and settings_data.selected_theme then
-			os:set_theme(settings_data.selected_theme)
+			mtos:set_theme(settings_data.selected_theme)
 			settings_data.selected_theme = nil
-			app:exit_app()
 		end
 	end
 })
diff --git a/apps/mail_app.lua b/apps/mail_app.lua
new file mode 100644
index 0000000..63e5d57
--- /dev/null
+++ b/apps/mail_app.lua
@@ -0,0 +1,249 @@
+-- based on https://github.com/cheapie/mail
+
+laptop.register_app("mail", {
+	app_name = "Mail",
+	app_icon = "laptop_email_letter.png",
+	app_info = "Write mails to other players",
+	formspec_func = function(app, mtos)
+		local cloud = app:get_cloud_storage_ref("mail")
+		if not mtos.appdata.os.last_player then
+			mtos:set_app() -- no player. Back to launcher
+			return false
+		end
+
+		if not cloud[mtos.appdata.os.last_player] then
+			mtos:set_app("mail:newplayer")
+			return false
+		end
+		local account = cloud[mtos.appdata.os.last_player]
+		account.selected_box = account.selected_box or "inbox"
+		account.selected_index = nil -- will be new determinated by selectedmessage
+		local box = account[account.selected_box] -- inbox or outbox
+
+		local formspec =
+				"label[4,-0.31;Welcome "..mtos.appdata.os.last_player.."]"..
+				"tablecolumns[" ..
+						"image,align=center,1=laptop_mail.png,2=laptop_mail_read.png;"..  --icon column
+						"color;"..	-- subject and date color
+						"text;".. -- subject
+						"text,padding=1.5;".. -- sender
+						"text,padding=1.5,align=right]".. -- date
+				"table[0,0.5;7.5,8.2;message;"
+
+		if box and box[1] then
+			for idx,message in ipairs(box) do
+				if idx > 1 then
+					formspec = formspec..','
+				end
+				-- set read/unread status
+				if account.selected_box == "sentbox" then
+					formspec = formspec .. "1,#88FF88," -- unread
+				elseif not message.is_read then
+					formspec = formspec .. "1,#FF8888," -- unread
+				else
+					formspec = formspec .. "2,#FFFFFF," -- read
+				end
+
+				-- set subject
+				if not message.subject or message.subject == "" then
+					formspec = formspec .. "(No subject),"
+				elseif string.len(message.subject) > 30 then
+					formspec = formspec .. minetest.formspec_escape(string.sub(message.subject,1,27)) .. "...,"
+				else
+					formspec = formspec .. minetest.formspec_escape(message.subject) .. ","
+				end
+
+				-- set sender or receiver
+				if account.selected_box == "inbox" then
+					formspec = formspec..minetest.formspec_escape(message.sender or "") ..","  -- body
+				else
+					formspec = formspec..minetest.formspec_escape(message.receiver or "") ..","  -- body
+				end
+
+				-- set date
+				formspec = formspec .. os.date("%c", message.time) -- timestamp
+
+				-- handle marked line
+				if account.selectedmessage and
+						message.sender == account.selectedmessage.sender and
+						message.subject == account.selectedmessage.subject and
+						message.time == account.selectedmessage.time and
+						message.body == account.selectedmessage.body then
+					account.selected_index = idx
+				end
+			end
+			formspec = formspec .. ";"..(account.selected_index or "").."]"
+		else
+			formspec = formspec .. ",,No mail :(]"
+		end
+
+		-- toggle inbox/sentbox
+		if account.selected_box == "inbox" then
+			formspec = formspec .. mtos.theme:get_button('0,9;1.5,1', 'minor', 'switch_sentbox', 'Sentbox', 'Show sent messages')
+		else
+			formspec = formspec .. mtos.theme:get_button('0,9;1.5,1', 'minor', 'switch_inbox', 'Inbox', 'Show received messages')
+		end
+
+		formspec = formspec .. "image_button[1.7,9;1,1;"..mtos.theme.minor_button.."^laptop_email_new.png;new;]tooltip[new;New message]"
+		if account.newmessage then
+			formspec = formspec .. "image_button[2.7,9;1,1;"..mtos.theme.minor_button.."^laptop_email_edit.png;continue;]tooltip[continue;Continue last message]"
+		end
+
+		if account.selectedmessage then
+			formspec = formspec ..
+					"image_button[3.7,9;1,1;"..mtos.theme.minor_button.."^laptop_email_reply.png;reply;]tooltip[reply;Reply]"..
+					"image_button[4.7,9;1,1;"..mtos.theme.minor_button.."^laptop_email_forward.png;forward;]tooltip[forward;Forward]"..
+					"image_button[5.7,9;1,1;"..mtos.theme.minor_button.."^laptop_email_trash.png;delete;]tooltip[delete;Delete]"
+			if account.selected_box == "inbox" then
+				if not account.selectedmessage.is_read then
+					formspec = formspec .. "image_button[6.7,9;1,1;"..mtos.theme.minor_button.."^laptop_mail_read.png;markread;]tooltip[markread;Mark message as read]"
+				else
+					formspec = formspec .. "image_button[6.7,9;1,1;"..mtos.theme.minor_button.."^laptop_mail.png;markunread;]tooltip[markunread;Mark message as unread]"
+				end
+			end
+			if account.selected_box == "inbox" then
+				formspec = formspec .. mtos.theme:get_label('8,0.5', "From: "..(account.selectedmessage.sender or ""))
+			else
+				formspec = formspec .. mtos.theme:get_label('8,0.5', "To: "..(account.selectedmessage.receiver or ""))
+			end
+
+			formspec = formspec .. mtos.theme:get_label('8,1', "Subject: "..(account.selectedmessage.subject or ""))..
+					"background[8,1.55;6.92,7.3;gui_formbg.png]"..
+					"textarea[8.25,1.5;7,8.35;body;;"..(minetest.formspec_escape(account.selectedmessage.body) or "").."]"
+		end
+		return formspec
+	end,
+	receive_fields_func = function(app, mtos, fields, sender)
+		if sender:get_player_name() ~= mtos.appdata.os.last_player then
+			mtos:set_app() -- wrong player. Back to launcher
+			return
+		end
+
+		local cloud = app:get_cloud_storage_ref("mail")
+		local account = cloud[mtos.appdata.os.last_player]
+		if not account then
+			mtos:set_app() -- wrong player. Back to launcher
+			return
+		end
+		account.selected_box = account.selected_box or "inbox"
+		local box = account[account.selected_box] -- inbox or outbox
+
+		-- Set read status if 2 seconds selected
+		if account.selected_index and account.selectedmessage and account.selected_box == "inbox" and
+				account.selected_timestamp and (os.time() - account.selected_timestamp) > 1 then
+			account.selectedmessage.is_read = true
+		end
+
+		-- process input
+		if fields.message then
+			local event = minetest.explode_table_event(fields.message)
+			account.selectedmessage = box[event.row]
+			if account.selectedmessage then
+				account.selected_index = event.row
+				account.selected_timestamp = os.time()
+			else
+				account.selected_index = nil
+			end
+		elseif fields.new then
+			account.newmessage = {}
+			mtos:set_app("mail:compose")
+		elseif fields.continue then
+			mtos:set_app("mail:compose")
+		elseif fields.switch_sentbox then
+			account.selected_box = "sentbox"
+			account.selectedmessage = nil
+		elseif fields.switch_inbox then
+			account.selected_box = "inbox"
+			account.selectedmessage = nil
+		elseif account.selected_index then
+			if fields.delete then 
+				table.remove(box, account.selected_index)
+				account.selectedmessage = nil
+			elseif fields.reply then
+				account.newmessage = {}
+				account.newmessage.receiver = account.selectedmessage.sender
+				account.newmessage.subject = "Re: "..(account.selectedmessage.subject or "")
+				account.newmessage.body = "Type your reply here."..string.char(10)..string.char(10).."--Original message follows--"..string.char(10)..(account.selectedmessage.body or "")
+				mtos:set_app("mail:compose")
+			elseif fields.forward then
+				account.newmessage = {}
+				account.newmessage.subject = "Fw: "..(account.selectedmessage.subject or "")
+				account.newmessage.body = "Type your reply here."..string.char(10)..string.char(10).."--Original message follows--"..string.char(10)..(account.selectedmessage.body or "")
+				mtos:set_app("mail:compose")
+			elseif fields.markread then
+				account.selectedmessage.is_read = true
+			elseif fields.markunread then
+				account.selectedmessage.is_read = false
+				account.selected_timestamp = nil -- Stop timer
+			end
+		end
+	end
+})
+
+laptop.register_view("mail:newplayer", {
+	formspec_func = function(app, mtos)
+		return mtos.theme:get_label('1,3', "No mail account for player "..mtos.appdata.os.last_player.. " found. Do you like to create a new account?")..
+				mtos.theme:get_button('1,4;3,1', 'major', 'create', 'Create account')
+	end,
+	receive_fields_func = function(app, mtos, fields, sender)
+		if sender:get_player_name() ~= mtos.appdata.os.last_player then
+			mtos:set_app() -- wrong player. Back to launcher
+			return
+		end
+		if fields.create then
+			local cloud = app:get_cloud_storage_ref("mail")
+			cloud[mtos.appdata.os.last_player] = {
+				inbox = {},
+				sentbox = {}
+			}
+			app:back_app()
+		elseif fields.os_back then
+			app:exit_app()
+		end
+	end
+})
+
+-- Write new mail
+laptop.register_view("mail:compose", {
+	formspec_func = function(app, mtos)
+		local cloud = app:get_cloud_storage_ref("mail")
+		local account = cloud[mtos.appdata.os.last_player]
+		account.newmessage = account.newmessage or {}
+		local message = account.newmessage
+
+		local formspec = "background[-0.1,0.4;4.2,2.4;gui_formbg.png]"..
+				"field[0.25,1;4,1;receiver;To:;%s]field[0.25,2;4,1;subject;Subject:;%s]"..
+				"background[0,3.05;7.95,3.44;gui_formbg.png]"..
+				"textarea[0.25,3;8,4;body;;%s]"..
+				mtos.theme:get_button("0,8;2,1", "major", "send", "Send message")
+		formspec = string.format(formspec,minetest.formspec_escape(message.receiver or ""),minetest.formspec_escape(message.subject or ""),minetest.formspec_escape(message.body or ""))
+		if message.receiver and not cloud[message.receiver] then
+			formspec = formspec..mtos.theme:get_label('2.3,8', "invalid receiver player")
+		end
+		return formspec
+	end,
+	receive_fields_func = function(app, mtos, fields, sender)
+		if sender:get_player_name() ~= mtos.appdata.os.last_player then
+			mtos:set_app() -- wrong player. Back to launcher
+			return
+		end
+
+		local cloud = app:get_cloud_storage_ref("mail")
+		local account = cloud[mtos.appdata.os.last_player]
+		account.newmessage = account.newmessage or {}
+		local message = account.newmessage
+
+		message.receiver = fields.receiver or message.receiver
+		message.sender = mtos.appdata.os.last_player
+		message.time = os.time()
+		message.subject = fields.subject or message.subject
+		message.body = fields.body or message.body
+
+		if fields.send and message.receiver and cloud[message.receiver] then
+			table.insert(cloud[message.receiver].inbox, message)
+			table.insert(account.sentbox, table.copy(message))
+			account.newmessage = nil
+			app:back_app()
+		end
+	end
+})
diff --git a/apps/stickynote_app.lua b/apps/stickynote_app.lua
index b635e7e..85ff5b1 100644
--- a/apps/stickynote_app.lua
+++ b/apps/stickynote_app.lua
@@ -6,7 +6,8 @@ laptop.register_app("stickynote", {
 		local data = app:get_storage_ref()
 		data.text = data.text or ""
 
-		return "textarea[0.35,0.35;15.08,10.5;text;;"..minetest.formspec_escape(data.text).."]"
+		return "background[0,0.35;15.2,9.2;gui_formbg.png]"..
+				"textarea[0.35,0.35;15.08,10.5;text;;"..minetest.formspec_escape(data.text).."]"
 	end,
 	receive_fields_func = function(app, os, fields, sender)
 		if fields.text then
diff --git a/demo_apps.lua b/demo_apps.lua
index 7b76e74..c96f03e 100644
--- a/demo_apps.lua
+++ b/demo_apps.lua
@@ -3,36 +3,36 @@ laptop.register_app("demo1", {
 	app_name = "Demo App",
 	app_icon = "laptop_setting_wrench.png",
 	app_info = "The first and simple demo app",
-	formspec_func = function(app, os)
-		return 'image_button[5,5;3,1;'..os.theme.major_button..';next;Second screen]'
+	formspec_func = function(app, mtos)
+		return mtos.theme:get_button('5,5;3,1', 'major', 'next', 'Second screen')
 	end,
-	receive_fields_func = function(app, os, fields, sender)
+	receive_fields_func = function(app, mtos, fields, sender)
 		if fields.next then
-			os:set_app("demo1_view2")
+			mtos:set_app("demo1_view2")
 		end
 	end
 })
 
 laptop.register_view("demo1_view2", {
 	app_info = "Second screen in Demo App 1",
-	formspec_func = function(app, os)
-		return "label[1,5;Use the framework buttons to navigate back or cancel]"
+	formspec_func = function(app, mtos)
+		return mtos.theme:get_label('1,5', "Use the framework buttons to navigate back or cancel")
 	end,
-	receive_fields_func = function(app, os, fields, sender)
+	receive_fields_func = function(app, mtos, fields, sender)
 	end
 })
 
 
 laptop.register_app("demo2", {
 	app_name = "Demo App 2",
-	formspec_func = function(app, os)
+	formspec_func = function(app, mtos)
 		local data = app:get_storage_ref()
 		data.counter = data.counter or 1
 
 		return 'button[3,1;5,1;count;Click: '..data.counter..']'..
 				'button[3,3;5,1;back;Back to launcher]'
 	end,
-	receive_fields_func = function(app, os, fields, sender)
+	receive_fields_func = function(app, mtos, fields, sender)
 		if fields.count then
 			local data = app:get_storage_ref()
 			data.counter = data.counter + 1
diff --git a/node_fw.lua b/node_fw.lua
index 451e07a..291052d 100644
--- a/node_fw.lua
+++ b/node_fw.lua
@@ -4,12 +4,12 @@ laptop.node_config = {}
 local function after_place_node(pos, placer, itemstack, pointed_thing)
 	local appdata = minetest.deserialize(itemstack:get_meta():get_string("laptop_appdata"))
 	if appdata then
-		local os = laptop.os_get(pos)
-		os.appdata = appdata
-		os.appdata.launcher = os.appdata.launcher or {}
-		os.appdata.os = os.appdata.os or {}
-		os.appdata.os.stack = os.appdata.os.stack or {}
-		os:save()
+		local mtos = laptop.os_get(pos)
+		mtos.appdata = appdata
+		mtos.appdata.launcher = mtos.appdata.launcher or {}
+		mtos.appdata.os = mtos.appdata.os or {}
+		mtos.appdata.os.stack = mtos.appdata.os.stack or {}
+		mtos:save()
 	end
 end
 
@@ -30,38 +30,38 @@ local function after_dig_node(pos, oldnode, oldmetadata, digger)
 end
 
 local function on_construct(pos)
-	local os = laptop.os_get(pos)
+	local mtos = laptop.os_get(pos)
 	local node = minetest.get_node(pos)
 	local hwdef = laptop.node_config[node.name]
 	if hwdef.custom_theme then -- initial only
-		os:set_theme(hwdef.custom_theme)
+		mtos:set_theme(hwdef.custom_theme)
 	end
 	if hwdef.hw_state then
-		os[hwdef.hw_state](os)
+		mtos[hwdef.hw_state](mtos)
 	else
-		os:power_off()
+		mtos:power_off()
 	end
-	os:set_infotext(hwdef.hw_infotext)
+	mtos:set_infotext(hwdef.hw_infotext)
 end
 
 local function on_punch(pos, node, puncher)
-	local os = laptop.os_get(pos)
+	local mtos = laptop.os_get(pos)
 	local hwdef = laptop.node_config[node.name]
 	if hwdef.next_node then
 		local hwdef_next = laptop.node_config[hwdef.next_node]
 		if hwdef_next.hw_state then
-			os[hwdef_next.hw_state](os, hwdef.next_node)
+			mtos[hwdef_next.hw_state](mtos, hwdef.next_node)
 		else
-			os:swap_node(hwdef.next_node)
-			os:save()
+			mtos:swap_node(hwdef.next_node)
+			mtos:save()
 		end
-		os:set_infotext(hwdef_next.hw_infotext)
+		mtos:set_infotext(hwdef_next.hw_infotext)
 	end
 end
 
 local function on_receive_fields(pos, formname, fields, sender)
-	local os = laptop.os_get(pos)
-	os:receive_fields(fields, sender)
+	local mtos = laptop.os_get(pos)
+	mtos:receive_fields(fields, sender)
 end
 
 function laptop.register_hardware(name, hwdef)
diff --git a/nodes.lua b/nodes.lua
index dce14a9..4189e01 100644
--- a/nodes.lua
+++ b/nodes.lua
@@ -73,7 +73,7 @@ laptop.register_hardware("laptop:cube", {
 	description = "CUBE PC",
 	infotext = "CUBE PC",
 	sequence = { "off", "on"},
-	custom_theme = "red",
+	custom_theme = "Red",
 	node_defs = {
 		["on"] = {
 			hw_state = "power_on",
diff --git a/os.lua b/os.lua
index d831678..25052fa 100644
--- a/os.lua
+++ b/os.lua
@@ -58,16 +58,7 @@ end
 -- Get given or current theme
 function os_class:get_theme(theme)
 	local theme_sel = theme or self.appdata.os.theme
-	local ret = table.copy(laptop.themes.default)
-	if theme_sel and laptop.themes[theme_sel] then
-		for k,v in pairs(laptop.themes[theme_sel]) do
-			ret[k] = v
-		end
-		ret.name = theme_sel
-	else
-		ret.name = "default"
-	end
-	return ret
+	return laptop.get_theme(theme_sel)
 end
 
 -- Set current theme
diff --git a/textures/email_edit.png b/textures/laptop_email_edit.png
similarity index 100%
rename from textures/email_edit.png
rename to textures/laptop_email_edit.png
diff --git a/textures/email_forward.png b/textures/laptop_email_forward.png
similarity index 100%
rename from textures/email_forward.png
rename to textures/laptop_email_forward.png
diff --git a/textures/email_new.png b/textures/laptop_email_new.png
similarity index 100%
rename from textures/email_new.png
rename to textures/laptop_email_new.png
diff --git a/textures/email_reply.png b/textures/laptop_email_reply.png
similarity index 100%
rename from textures/email_reply.png
rename to textures/laptop_email_reply.png
diff --git a/textures/email_trash.png b/textures/laptop_email_trash.png
similarity index 100%
rename from textures/email_trash.png
rename to textures/laptop_email_trash.png
diff --git a/textures/mail.png b/textures/laptop_mail.png
similarity index 100%
rename from textures/mail.png
rename to textures/laptop_mail.png
diff --git a/textures/mail_read.png b/textures/laptop_mail_read.png
similarity index 100%
rename from textures/mail_read.png
rename to textures/laptop_mail_read.png
diff --git a/themes.lua b/themes.lua
index c4ef4f2..10c4884 100644
--- a/themes.lua
+++ b/themes.lua
@@ -7,6 +7,7 @@ laptop.themes = {
 		back_button = "laptop_theme_freedom_back_button.png",
 		exit_button = "laptop_theme_freedom_exit_button.png",
 		app_button = "laptop_theme_freedom_app_button.png",
+		textcolor = "#000000",
 	},
 }
 
@@ -25,4 +26,30 @@ for _, file in ipairs(theme_list) do
 	if file:sub(-10) == '_theme.lua' then
 		dofile(theme_path..file)
 	end
-end
\ No newline at end of file
+end
+
+local theme_class = {}
+theme_class.__index = theme_class
+
+-- get prepared button textures
+function theme_class:get_button(area, prefix, code, text, tooltip)
+	return'image_button['..area..';'..self[prefix.."_button"]..';'..code..';'.. minetest.colorize(self[prefix.."_textcolor"] or self.textcolor,minetest.formspec_escape(text))..']'..
+			"tooltip["..code..";"..minetest.formspec_escape(tooltip or text).."]"
+end
+-- Get themed label
+function theme_class:get_label(area, label)
+	return'label['..area..';'..minetest.colorize(self.textcolor, minetest.formspec_escape(label))..']'
+end
+
+function laptop.get_theme(theme_name)
+	local self = setmetatable(table.copy(laptop.themes.default), theme_class)
+	if theme_name and laptop.themes[theme_name] then
+		for k,v in pairs(laptop.themes[theme_name]) do
+			self[k] = v
+		end
+		self.name = theme_name
+	else
+		self.name = "default"
+	end
+	return self
+end
diff --git a/themes/basic_theme.lua b/themes/basic_theme.lua
index 1b53097..6cef136 100644
--- a/themes/basic_theme.lua
+++ b/themes/basic_theme.lua
@@ -1,9 +1,10 @@
-laptop.register_theme("Basic", {
-	launcher_bg = "laptop_theme_basic_launcher_bg.png",
-	app_bg = "laptop_theme_basic_app_bg.png",
-	major_button = "laptop_theme_basic_button.png",
-	minor_button = "laptop_theme_basic_button.png",
-	back_button = "blank.png",
-	exit_button = "blank.png",
-	app_button = "blank.png",
-})
\ No newline at end of file
+laptop.register_theme("Basic", {
+	launcher_bg = "laptop_theme_basic_launcher_bg.png",
+	app_bg = "laptop_theme_basic_app_bg.png",
+	major_button = "laptop_theme_basic_button.png",
+	minor_button = "laptop_theme_basic_button.png",
+	back_button = "blank.png",
+	exit_button = "blank.png",
+	app_button = "blank.png",
+	textcolor = "#FFFFFF",
+})
diff --git a/themes/blue_theme.lua b/themes/blue_theme.lua
index 21d8f2f..87fc4a4 100644
--- a/themes/blue_theme.lua
+++ b/themes/blue_theme.lua
@@ -1,9 +1,9 @@
-laptop.register_theme("Blue", {
-	launcher_bg = "laptop_theme_blue_launcher_bg.png",
-	app_bg = "laptop_theme_blue_app_bg.png",
-	major_button = "laptop_theme_blue_major_button.png",
-	minor_button = "laptop_theme_minor_button.png",
-	back_button = "laptop_theme_blue_back_button.png",
-	exit_button = "laptop_theme_blue_exit_button.png",
-		app_button = "laptop_theme_blue_app_button.png",
+laptop.register_theme("Blue", {
+	launcher_bg = "laptop_theme_blue_launcher_bg.png",
+	app_bg = "laptop_theme_blue_app_bg.png",
+	major_button = "laptop_theme_blue_major_button.png",
+	minor_button = "laptop_theme_minor_button.png",
+	back_button = "laptop_theme_blue_back_button.png",
+	exit_button = "laptop_theme_blue_exit_button.png",
+		app_button = "laptop_theme_blue_app_button.png",
 })
\ No newline at end of file
diff --git a/themes/cubic_theme.lua b/themes/cubic_theme.lua
index 57637e1..18b5a3d 100644
--- a/themes/cubic_theme.lua
+++ b/themes/cubic_theme.lua
@@ -1,9 +1,9 @@
-laptop.register_theme("Cubic", {
-	launcher_bg = "laptop_theme_cubic_launcher_bg.png",
-	app_bg = "laptop_theme_cubic_app_bg.png",
-	major_button = "laptop_theme_cubic_major_button.png",
-	minor_button = "laptop_theme_minor_button.png",
-	back_button = "laptop_theme_cubic_back_button.png",
-	exit_button = "laptop_theme_cubic_exit_button.png",
-		app_button = "laptop_theme_cubic_app_button.png",
+laptop.register_theme("Cubic", {
+	launcher_bg = "laptop_theme_cubic_launcher_bg.png",
+	app_bg = "laptop_theme_cubic_app_bg.png",
+	major_button = "laptop_theme_cubic_major_button.png",
+	minor_button = "laptop_theme_minor_button.png",
+	back_button = "laptop_theme_cubic_back_button.png",
+	exit_button = "laptop_theme_cubic_exit_button.png",
+		app_button = "laptop_theme_cubic_app_button.png",
 })
\ No newline at end of file
diff --git a/themes/magma_theme.lua b/themes/magma_theme.lua
index 497626f..b5570c6 100644
--- a/themes/magma_theme.lua
+++ b/themes/magma_theme.lua
@@ -1,9 +1,9 @@
-laptop.register_theme("Magma", {
-	launcher_bg = "laptop_theme_magma_launcher_bg.png",
-	app_bg = "laptop_theme_magma_app_bg.png",
-	major_button = "laptop_theme_magma_major_button.png",
-	minor_button = "laptop_theme_minor_button.png",
-	back_button = "laptop_theme_magma_back_button.png",
-	exit_button = "laptop_theme_magma_exit_button.png",
-		app_button = "laptop_theme_magma_app_button.png",
+laptop.register_theme("Magma", {
+	launcher_bg = "laptop_theme_magma_launcher_bg.png",
+	app_bg = "laptop_theme_magma_app_bg.png",
+	major_button = "laptop_theme_magma_major_button.png",
+	minor_button = "laptop_theme_minor_button.png",
+	back_button = "laptop_theme_magma_back_button.png",
+	exit_button = "laptop_theme_magma_exit_button.png",
+		app_button = "laptop_theme_magma_app_button.png",
 })
\ No newline at end of file
diff --git a/themes/red_theme.lua b/themes/red_theme.lua
index 0a6c4c6..b435dcd 100644
--- a/themes/red_theme.lua
+++ b/themes/red_theme.lua
@@ -1,9 +1,9 @@
-laptop.register_theme("Red", {
-	launcher_bg = "laptop_theme_red_launcher_bg.png",
-	app_bg = "laptop_theme_red_app_bg.png",
-	major_button = "laptop_theme_red_major_button.png",
-	minor_button = "laptop_theme_minor_button.png",
-	back_button = "laptop_theme_red_back_button.png",
-	exit_button = "laptop_theme_red_exit_button.png",
-		app_button = "laptop_theme_red_app_button.png",
+laptop.register_theme("Red", {
+	launcher_bg = "laptop_theme_red_launcher_bg.png",
+	app_bg = "laptop_theme_red_app_bg.png",
+	major_button = "laptop_theme_red_major_button.png",
+	minor_button = "laptop_theme_minor_button.png",
+	back_button = "laptop_theme_red_back_button.png",
+	exit_button = "laptop_theme_red_exit_button.png",
+		app_button = "laptop_theme_red_app_button.png",
 })
\ No newline at end of file