FormSync

FormSync lets you place two videos side by side and play them together — a simple app for checking form.

Compare any kind of movement: dance, golf, tennis, baseball, training, and more. Put a reference next to yourself, or your past form next to today's, and spot the differences at a glance.

Features
- Pick two videos from your camera roll and view them side by side
- Play and pause both videos at the same time
- A shared seek bar to move both to the same position
- Slow-motion playback (0.25x / 0.5x / 0.75x / 1x)
- Set a start point for each video and fine-tune it in 0.05s steps
- Jump to start / skip forward 10s / back 10s
- Pinch to zoom in and check the fine details up close
- Landscape mode on the compare screen
- Swap one video and keep the other — compare new takes against your reference, one after another
- Draw straight lines to compare form — angle and alignment (PRO)
- Auto-detect pose — full-body skeleton and spine angle drawn in one tap (PRO)
- Export your comparison as a single side-by-side video (saved to your camera roll, ready to share)
- Save your comparisons to history, name them, and revisit them

Free
- Compare any videos — preview plays 10 seconds from your chosen start points
- Export comparisons up to 10 seconds (with a small watermark)
- Keep your 5 most recent comparisons in history

PRO (one-time purchase)
- Play and compare videos in full length
- Draw straight lines to compare form — angle and alignment, baked into your exports too
- Auto-detect pose — full-body skeleton plus spine angle for your golf swing, in one tap
- Export full-length comparisons (watermark can be turned off)
- Keep unlimited history

All videos are processed on your device and are never uploaded to a server.

For iPhone.