I'm currently working on a Sencha Touch project making an Entrepreneur application, which will be released in a couple of months... Stay tuned! I only want say that it is a bit more complex than this example... but you have to start with something, right?!
Next step: The framework
Step 1: Host your Sencha Touch App on your Raspberry Pi!
If you really are thinking of making an App, you should look at http://docs.sencha.com/touch/2-0/#!/example
Creation of an App
This was my first try, so I made some minor good codelines, but even though.... it works!! (Not in Internet Explorer, because the framework doesn't support it, but who has a Windows phone... ;).
The basics are:
Define your app in a MVC fashion:
The Models take care of data structure.
The Views displays data.
The Controllers take care of logic.
The app.js holds the application.
(And the other files are filed as above... if it is a big App).
Read more at http://docs.sencha.com/touch/2-0/#!/guide/getting_started
(Mine is not a good example, but as I said it works!)