Detection of Home Screen [Android]

I am looking for a very simple application [fully created in Ecllipse] which will do the following: > Detect when a user is in the Home Screen [It does not matter which page] of their launcher and if he/she is on the home screen, display a message via Toast saying "Home". If they have left the home screen [Including going to the App drawer], the Toast message should read "Out". [See enclosed pictures for how it should look] > This app MUST work for: 1. ICS & KitKat & JB 2. Default android launcher for the above. 3. Nova launcher 4. Go Launcher If you can make it work with more launchers OR BETTER a generic one for every launchers, I will be willing to pay more as bonus which we can agree on prior to app development.