What is required is a simple proof-of-concept app which would be able to connect to a variety of bluetooth keyboards, trackpads and mice (i.e. HID devices) and produce the following results uniformly across all devices:
When a key is pressed, the app should print the appropriate keycode on the screen
Left / right / middle mouse buttons should be differentiated as well
When the trackpad is used, the app should print the coordinates or distances the finger has traveled.
This would need to run on all Android 2.1+ devices, without rooting or modifying the firmware in any way.
There is scope for more work for the successful candidate who showcases the correct skills