any link to back this up?
I find that killing app saves me more battery.
Maybe for those frequently used apps is we keep them in background.
In the email shared with 9to5Mac, Apple iOS chief Craig Federighi jumps in to answer Caleb’s question. The message headers have been verified for legitimacy. This is the arguably the strongest opposition from Apple executives on record in reply to the ‘quit all your apps’ superstition; Apple’s official support pages say that force-quitting should only be used on a case-by-case basis when an app freezes or misbehaves.
https://9to5mac.com/2016/03/10/should-you-quit-ios-apps-answer/
Side note as an Application developer for iOS and Android. On iOS we can barely keep apps alive for any longer than 3 min max unless we ask for very specific and special things.
Apps that play audible content to the user while in the background, such as a music player app
Apps that record audio content while in the background
Apps that keep users informed of their location at all times, such as a navigation app
Apps that support Voice over Internet Protocol (VoIP)
Apps that need to download and process new content regularly
These apps can run but they must be declared explicitly