If you've noticed that your device becomes too slow, use the Auto-start Manager app to check the running apps and their memory use. If you don't need these apps at the moment, you can disable or deny them to release more memory.
There are two scenarios to release the app’s memory:
If the app is currently running and its auto-start setting is set to Allow, move the slider to Deny to release the memory.
If the app is currently running and its auto-start setting is set to Deny, move the slider to Allow then move it back to Deny to release the memory.
Note: In this scenario, the Auto-start Manager displays the app’s memory usage even though the app is set to Deny.