How to control Activity flow - Back button versus Home button

Question

I have 3 activities in my application:

Activity1 -> Activity2 -> Activity3

Inside Activity3, if the user presses Back, I would like t

Answer 1

On main activity add:

android:launchMode="singleTask" android:clearTaskOnLaunch="true"

On the others add:

android:finishOnTaskLaunch="true"

This way it will kill off any activity when returning to the app after being in background.