Simple HTML5/CSS3/Javascript/JQuery Mobile/JSON Website for Future Works

Please create a simple HTML5/CSS3/Javascript/JQuery Mobile/JSON PhoneGap application (see [login to view URL]) that should do some simple computation (e.g. add VAT to a value entered by the user) That app should either be for iOS, android or blackberry 10 and should use a resposive web design (JQuery Mobile) Please focus on these topics: The user interface should be simple and elegant (light colors, thin fonts ...) surprise me ;-) The javascript code should be well structured. Also the app should manage to query an external datasource (choose whatever you want) using JSON/AJAX and display the data from the datasource in the UI (eg in a second tabpage ...). Be aware that might have to use JSONP or CORS, if you access data from a different domain. Bonus points if the code is well documented in an attached html5 file explaining the use of each technology for easy evaluation. The developer will be selected to work in future projects, so make a good joob!