What Rewind does to your clip, and the two things that surprise people most: the ten-second limit, and HDR previews that refuse to run backward.
Because the clip is HDR (10-bit HEVC), and iOS can't scrub that format backward in a live preview. It's a limitation of the player, not of the export, your exported video still contains the true reversed frames and plays back and forth exactly as it should. Rewind tells you when this is happening rather than leaving you guessing.
The bouncy loop wants between 1 and 10 seconds. Shorter than a second and there's no loop to see; longer than ten and it stops reading as a loop and starts reading as a video that happens to run backward. Trim the window down to the moment that's worth repeating.
No. Reading the clip, reversing it, and writing the finished loop all happen on your device. There's no server, no account, no login. It leaves your phone only when you share it yourself.
Never. Rewind writes a new video and leaves the original untouched. Trimming only changes which part of the clip gets used, so you can always drag the handles back out.
It plays forward on the forward segments and reversed on the reverse segments, which is exactly as strange and as fun as it sounds. If you'd rather have silence, one tap on the mute toggle strips the audio entirely.
Every place the video changes direction gets a short crossfade, so there's no visual pop at the turn. It's the difference between a loop that looks made and a loop that looks stitched.
To read the clip you pick and to save the finished loop back, iOS treats those as two separate permissions. You can also share a video into Rewind from another app and export it straight back out with the share sheet.
One small banner, and nothing more, no interstitials, no video ads. Where the law requires it you'll get a consent prompt on first launch, and you can revisit that choice any time from Settings → Manage Privacy Choices.
Apple's App Tracking Transparency prompt. Decline it and Rewind behaves identically, the banner just shows less relevant ads.
No account, no sign-up, no subscription. Rewind is free and works offline.