Some applications aren't ended completely when your phone returns to standby mode, but keep running in the background unless you end them from the list of active applications. Follow these instructions to end active applications.
Step 1 of 5
Find "Task Manager"
Press All apps.
Step 2 of 5
Find "Task Manager"
Press Task Manager.
Step 3 of 5
End active applications
To end an application: Press X next to the required application.
Step 4 of 5
End active applications
To end all applications: Press Kill all.
Step 5 of 5
Exit
Press the Home key to return to standby mode.
Find "Task Manager"
Press All apps.
Press Task Manager.
End active applications
To end an application: Press X next to the required application.