Why the still you pull out is better than the screenshot you'd have taken, and what all those format options are for.
A screenshot captures your screen, so it's the size of your display, with the video scaled down to fit it, and often the playback controls baked in. Video Freezer reaches into the video file and pulls out the actual frame at its actual size. A 4K video gives you a 4K photo. That's usually four times the pixels a screenshot would have given you, and none of the interface.
Because the video you opened isn't HDR. When the source is HDR, the video most recent iPhones shoot, Video Freezer offers an extra HEIC (HDR) format that keeps the full 10-bit range, so the bright parts of the frame stay bright instead of clipping to white. On an ordinary SDR clip there's nothing extra to preserve, so the option doesn't appear.
HEIC for the best quality-to-size ratio, and it's what your iPhone camera already uses. PNG when you need it lossless, or you're going to edit it further. JPEG when something old needs to open it. And HEIC (HDR), when it's offered, for the frame that deserves the full range.
Slide along the filmstrip to get close, then step one frame at a time until it's right, or jump a whole second forward and back when you're further off than that. The stride that lands, the blink that doesn't, the splash at its peak.
Yes, that's Range mode. Mark a start and an end and Video Freezer saves every frame between them at full resolution. For a longer span you can thin it out to every 2nd, 5th, or 10th frame instead of every single one. You get to page through the captured series before you commit, then save the whole set to your album at once.
No. Your video is read, never written. It isn't re-encoded, re-compressed, trimmed, or modified in any way, Video Freezer only ever adds a new photo.
Into its own "Video Freezer" album in Photos, so your grabs stay together and your camera roll doesn't turn into a contact sheet. You can also skip saving and share the still straight out of the app.
No. The frame is extracted on your device. There's no server, no account, no login.
One small banner, and nothing else. Where the law requires it you'll get a consent prompt on first launch, and Settings → Manage Privacy Choices lets you revisit it.
Apple's App Tracking Transparency prompt. Decline it and the app is unchanged; the banner simply shows less relevant ads.
No account, no sign-up, no subscription. Video Freezer is free and works offline.