I have an activity that essentially launches a CountDownTimer. I need this to continue running while using other Android apps, such as Gmail, and media players etc.
When I hit the back button, my Activity seems to quit. What do I need to do to keep it running when the user clicks the back/home keys etc.
Activities are not supposed to be doing anything when they are not visible. They are basically UI components.
You should be looking into services. These can run as a background process nd contain no UI.