Android 3.1 introduces Launch controls on stopped applications. However, there are no such features on android 2.3, some 4.X devices didn't implement it well. Furthermore, there are some way for apps to wakeup some stopped apps. "Prevent Running" hajacks several system API to prevent not-in-use apps in prevent list from running or keep running. Furthermore, it applies to system apps too, specially, support google-family apps(GAPPS).