Chest Fly Form Check
Wondering if your chest fly is solid? Prop up your phone — GOODREPS watches your shoulder angle (hip → shoulder → elbow) live and scores every rep while you train your chest, with shoulders assisting. Free in your browser today; coming to Google Play and the App Store.
Coming to Google Play & the App Store▶ Try The Form Check
LIVEHOW TO DO A PROPER CHEST FLY
Setup Stand facing the camera, arms open wide at shoulder height with a slight elbow bend.
- Bring the weights together in front of your chest in a wide arc.
- Squeeze your chest at the top.
- Open back out slowly to a stretch.
Same sheet as the ⓘ panel in the app — animated demo included.
THREE STEPS TO A SCORED CHEST FLY
Prop your phone and get in frame
Phone at roughly torso height, stand facing the camera. A quick camera test checks lighting, distance, and angle before you start.
The camera locks a 17-point skeleton on you
GOODREPS measures your shoulder angle (hip → shoulder → elbow) on-device — no wearables. Dumbbells on a bench (or floor flys if that is all you have).
Move — and watch the form bar
The bar fills from ~150° toward ~65° at the bottom. Cut range short and it tells you; full ROM is what counts.
WHAT THE CAMERA WATCHES
- Arms opening wide with a soft elbow, then hugging back together.
- Shoulders staying set on the bench — no shrugging into the neck.
- A controlled stretch at the bottom before the squeeze.
COMMON CHEST FLY MISTAKES
Turning it into a press
Elbows stay soft and fixed. If they bend and press, it is a bench press cousin.
Going dangerously deep
Stop when you feel a chest stretch, not a shoulder strain.
Clanking weights at the top
Squeeze without slamming. Soft finish, hard chest.
Arching off the bench for more height
Ribs stay down. The fly is horizontal adduction, not a circus bridge.
PRIVATE BY DESIGN
Pose detection runs in your browser via TensorFlow.js. Camera frames are analyzed in real time and immediately discarded — nothing is recorded, nothing leaves your phone, and we never see them. Sign-in is optional; skip it and everything stays local.
QUESTIONS, ANSWERED
Do I need any equipment to check my chest fly form?
Just your phone for most variations. Add free weights when the pattern is clean — the app still scores the movement either way.
Does it work in a home gym or low light?
Run the built-in camera test first — it checks your lighting, distance, and angle with live green checks before you start. If a rep still slips through, manual counting is always one tap away.
Is my camera feed uploaded anywhere?
No. Pose detection runs entirely on your phone, in your browser. Frames are analyzed in real time and immediately discarded — nothing is recorded, nothing is uploaded.
RELATED GUIDES
Free forever — camera counting for all 60 exercises, no account needed. Pro (voice coaching, programs, depth-camera form checks) is $7/mo, $49/yr, or $99 once. No ads, ever.