Do not close iPhone and iPad 'background' apps

It is a common belief that you should close apps running in background to improve performance and save battery life. Unfortunately, this is a myth that is not true in almost all situations.You should only close an app in the quick-launch (App Switcher) screen if it is "misbehaving" - not working right, or if it is using energy (as per Settings/Battery) and you don't need it at the present time. There are several reasons you should not close apps. The highlights are:

• First and foremost, they are not “running” in background. They are suspended.
• It doesn't do any good - there is nothing to be gained.
• It does not help battery life. To get an idea of how little would be saved by closing apps you can use Settings/Battery, as described here: How much battery energy does each app use? What this doesn't show is that it actually worsens battery life, because it takes more energy to load an app than to restart it from the "multitasking" screen.
• It does not make your phone faster (it actually makes it slower, because it takes longer to initialize an app from storage than to restart it from a suspended state).
• It does not "clean up" RAM memory (iOS is the expert about managing RAM; neither you nor any “cleanup” app can possibly "outthink" it and do a better job)

This last one is the easiest to explain; Older iPhones have 1 GB RAM; a few have 2 GB. The latest have 3 GB. That's it. If you have, say, 100 apps listed if you double-press the HOME button (or equivalent on phones that don't have one: How to force an app to close on your iPhone, iPad, or iPod touch - Apple Support) only the most recent 3 or 4 are in RAM at all; the rest of RAM holds iOS and its data. The remaining apps on the list are back on the storage medium, with only an entry in a table of open apps so they can be reloaded faster. And, as the first bullet says, NONE of them are "running"; they are all suspended, not using power, not using any other resources.

There has been a lot written about this subject; if you don't want to take my word for it, see these links from other experts.

• How about an expert from Apple: Apple’s software SVP says quitting multitasking apps not necessary, won’t offer improved battery life
• Still not convinced? See:Daring Fireball: Public Service Announcement: You Should Not Force Quit Apps on iOS
• Finally:No, Closing Background Apps on Your iPhone or iPad Won’t Make It Faster