Actually, he's completely wrong about multitasking on Android, and BTW, your father-in-law is (IMHO) wasting his time with "Advanced Task Killer". That app is in general a waste of time. Refer to my post elsewhere is this thread for more detail, but the short version is that apps don't need to be specifically killed on Android. Apps do not normally run in the background at all, they are stopped as soon as they're not user visible anymore. Apps that do wish to do things in the background, like play music, can register a service process, which is kind of like a background worker thread. The service process is the only thing that actually runs in the background.