AI squat form app: what actually works
A real AI squat form app watches every rep live and scores what matters — depth (range of motion) and tempo (control) — on your phone, without uploading video anywhere. One-off clip graders tell you about one set, once. Live scoring changes how you train: it catches the rep where your depth faded and turns form into a number the app can progress your weight from.
Why depth and tempo are the right signals
Depth is the single most measurable squat-technique variable, and the research says it matters: training deeper squats produced equal or greater growth of the quads, adductors and glutes compared with partial squats in controlled trials (Bloomquist et al. 2013; Kubo et al. 2019), and strength gains are specific to the range you train.
Tempo is the control signal — a rushed, bouncing descent is both a technique fault and a missed hypertrophy stimulus. A controlled eccentric is a standard coaching prescription for a reason.
One-off clip vs live scoring
Clip graders (upload a video, get a score) are useful, but they audit a single set after the fact. Live scoring runs during the workout: it counts each rep, scores it the moment you finish it, and speaks the feedback so you get it standing at the bar — closer to what a coach in the room actually does.
The second difference is what the score is used for. If form is a number the app trusts, it can gate your progression on it: hit your reps at depth and the weight goes up, miss and it holds. Form scoring becomes the engine of the program, not a party trick.
On-device matters
Filming yourself lifting is personal. Spotter analyses the camera stream entirely on the phone with Apple's Vision framework — the video is never uploaded, never stored, never leaves the device. Only anonymous numeric scores exist after the set. On-device also means zero latency: the rep count lands the instant you stand up.
How Spotter does it
Prop your phone side-on ~3 metres away. Spotter tracks your knee angle frame by frame, counts each rep, and scores depth and tempo per rep — live. It speaks the count and the coaching between sets, runs the rest timer, and auto-progresses every barbell lift's working weight from what you actually did. Full-body 5×5, powerlifting and hypertrophy programs included.
Answers
Can an app really score my squat form?
Yes, for the measurable fundamentals: depth (how deep you squat, via joint angles) and tempo (control of descent and ascent). On-device pose estimation is now accurate enough to do this live on a phone. Subtle elite-level cues still belong to a human coach.
Does Spotter upload my workout video?
No. The camera stream is analysed entirely on-device and never uploaded or stored. Only numeric rep scores exist after the set — those drive the coaching and progression.
What's the difference between Spotter and a form-check app?
Form-check apps grade one uploaded clip after the fact. Spotter scores every rep live during the workout and uses those scores to run your program — adding weight when you earn it, speaking coaching between sets, hands-free.
Related: Is my squat deep enough? · App that counts squat reps · How Spotter works