For the first time ever, iOS & iPadOS 18 offer a feature in the Photos app that users have wanted for a long time: looped video playback. This means that when previewing a video in your Photo Library, it will restart from the beginning and play again once the playback reaches its end for a continuous playback that never ends until you swipe away from it.
LoopVideos jailbreak tweak backports iOS 18’s looped video playback to pwned devices
