Basic Android App - Soft Key Protector

I am looking for someone who can write a fairly basic Android application to disable and intercept soft button events such as the back button, home button and menu buttons on the screen toolbar. When these keys are touched/clicked/tapped I want a prompt to appear to tell the user that if they want that button's default event to fire, they should double-tap them. And when they double-tap them, the default event of that key should fire. As simple as that. The settings screen should allow the user to turn the above functionality on or off, in other words to turn on or turn off locking the soft keys. This should be done via: - A check box that says "Lock Soft Keys" - A choice to activate the keys via double-tap or triple-tap - OK button to save the setting Other requirements: - App should have a small footprint and not require a lot of memory or a powerful processor to run - Must be reliable and bug-free -- this is of the utmost importance - Only need to support Android 4.x (Ice Cream Sandwich), but future versions may need to support older/newer versions of Android - Development should be done in such a manner that allows the app to be scalable in terms of functionality in future versions. For instance, future versions may be required to allow the user to specify a list of apps the locking of the soft keys should apply to - May need to disable other toolbar soft keys such as the date and time shortcut and have this as another configurable option - Code must be documented or thoroughly commented The candidate who develops this app: - Needs to have actual Adroid app development experience with at least one fully functional app (of any kind) that they have previously developed available for a demo. - Must be available for support or bug-fixing after development has been completed. - Should preferablybe interested in ongoing work on this and related apps