Well, this would be a great idea to have something like this for game controlling but I think this should be a part of the game.
If the game would be developed for device with a dual screen then such game pad should appear automatically.
I also tried a gamepad, but nothing too!
Then I created my own with the keyboard libretto.
I give you to put files in C: \ Program Files \ Toshiba \ Libretto \ tosswkb_skin
if you also create keyboard posted them here
attention to replace the file skintable.xml change the permissionsof the file property. to display the gamepad is the 7th keyboards! enjoy