Some applications aren't ended completely when you return to the home screen. If you don't end them from the list of active applications, they keep running in the background which may slow down your phone.
Step 1 of 3
End active applications
Press the Application key.
Step 2 of 3
End active applications
Slide your finger right on the required application.
Step 3 of 3
Return to the home screen
Press the Home key to return to the home screen.
End active applications
Press the Application key.
Slide your finger right on the required application.
