i need help! how to close apps

That is not an app you can stop. It's an information screen.

--Tapatalk on SGS3.
 
As the previous poster noted, that is simply a history of all of the apps and services that have been running since the last cycle that's being tracked began. Even if you go into the Task Manager and kill an app (not recommended BTW) it'll still show up in the history view.
If you fully charge the phone it'll reset that list.

Sent from my rooted, debloated, deodexed Sinclair ZX-80 running CM -0.001 using Tapatalk 4