FormSync: Swing & Form Compare
Side by side video analysis
Only for iPhone
Free · In‑App Purchases · Designed for iPhone. Not verified for macOS.
iPhone
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 (zoom is kept in your exports too)
- Landscape mode on the compare screen
- Swap one video and keep the other — compare new takes against your reference, one after another
- Mirror view — flip either video horizontally to match your reference's direction
- 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 video, landscape or vertical 9:16 (saved to your camera roll, ready to share)
- Set an end point and export just the range you want to show
- 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.
- New languages: Simplified Chinese, Traditional Chinese, and Korean
- Minor improvements
The developer, Hiroki Sugiyama, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Linked to You
The following data may be collected but it is not linked to your identity:
- Purchases
- Identifiers
- Usage Data
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- Hiroki Sugiyama
- Size
- 37.7 MB
- Category
- Photo & Video
- Compatibility
Requires iOS 15.1 or later.
- iPhone
Requires iOS 15.1 or later. - iPod touch
Requires iOS 15.1 or later. - Mac
Requires macOS 12.0 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 1.0 or later.
- iPhone
- Languages
English and 4 more
- English, Japanese, Korean, Simplified Chinese, Traditional Chinese
- Age Rating
4+
- 4+
- In-App Purchases
Yes
- PRO Upgrade $4.99
- Copyright
- © 2026 Hiroki Sugiyama