Report Issues, Bugs, Feature Suggestion in github issues section here

Closing background apps:
✓ Saves battery, extends battery life.
✓ Helps reduce device temperature.
✓ Helps save RAM.
✓ Saves processing power, i.e. reduces CPU usage of your device.
✓ Improves gaming performance of your device.
✓ Helps speed up your device.

Features:
✓ Lists User apps and System apps.
✓ Close all apps at once or Close multiple apps at once.
✓ Option to open at startup.
✓ Switch Layout as per your choice.

Supports:
✓ Android Phones.
✓ Tablets.
✓ Chromebook, Windows Subsystem for android.
✓ Fire TVs, Smart TVs, Android TVs. (Remote Friendly)

Force stop system app(s) only if you know what you are doing; be careful as it may affect your device adversely

When you select/click on app(s) it takes you to the app info screen of selected app(s); from where you are to select "Force Stop" in order to close the app.
Closing an app implies that you are aware that all the background functionality (service, periodic task, event receiver, alarm, widget update, push message) of this app will not be functional until you/your action(s) open the app again.

More info, help @ https://t.me/vishnunkmr