You can set the Boost+ app  to automatically stop unused apps from running in the background. 
 This helps save battery power.
- 
 From the Home screen, tap ![]() , and then find and tap Boost+. , and then find and tap Boost+.
- Tap Optimize background apps.
- Make sure the Optimize background apps On/Off switch is turned on.Boost+ lists down unused apps that are running in the background. 
- Tap an app under Auto stop to choose whether to always stop the app from running, stop when the app isn't running for a certain period of time, or always allow the app to run in the background.To auto stop an app after a period of inactivity, tap , and then choose how long an app is unused before it's automatically stopped.