Jaat Navigator is a Simple On-Screen Android Navigation App that i did for a friend of mine whose Hardware navigation system broke down. So here it is if you need might need it. Navigate through your device with this simple app. Goto settings>Accessibility>Services To enable it first.
If activated, you will now see Two button at the left and right bottom of your Screen, left is back key long-clicking will move buttons to navigation drawer, touch to re-enable it. Right key is the home Key , Long-clicking will reveal recent Applications.
Require Android 4.0+
Most Compatible 4.2(Recommended).