When you start your Android phone, some apps you've installed may launch automatically. This can slow your phone down and cause other apps to load slowly. Android has a built-in way to force running applications to close. You can locate applications that have started automatically and close them to free up memory on your phone.
Press the Menu button on your Android phone, then tap "Settings."
Tap the "Applications" option.
Touch the "Running Services" item on the screen.
Tap on the application that you want to close, then touch the "Stop" button.