Stand your phone up and start the set. AMC reads your joints from the camera, judges each rep against a trainer's criteria adjusted to your own body, and speaks up the moment something needs fixing — no wearables, no straps, no video sent anywhere.
There is no setup ritual. You are not asked to measure a distance or a tripod height — only to stand where your whole body fits in the frame.
No measured distance, no tripod height, no gyroscope. The only question that matters is whether your body is in the frame — and if it is not, AMC says so instead of guessing.
Two seconds of standing still sets your personal baseline. Depth and range are then read relative to you, so a long femur or a short torso is not mistaken for bad form.
Mid-set you get a single spoken correction — the one that matters most right now. A list of six things to fix while you are under load is not coaching.
AMC does not compare your rep to a reference video. It measures joint angles, normalizes them against your own baseline, and applies thresholds a trainer agreed to. That one decision is why the rest of the product behaves the way it does.
Template matching flags anyone whose proportions or tempo differ from the reference. Angle rules against your own baseline remove that false alarm at the source.
“Your knees are 12° narrower than your baseline” tells you what to move. A similarity score of 0.73 does not — and cannot be argued with, checked, or coached against.
Angle arithmetic is cheap, so judgment runs on the phone. Nothing has to be uploaded for a verdict, which is a privacy property and a latency one at once.
Labelled reps exist to measure the rules — what fraction of real errors was missed, and how often a good rep was wrongly flagged. The rules are the product; the data checks them.
Each error carries one of three severity levels, and the strongest correction is capped per error type by joint-load risk — the instruction never pushes you harder than the movement safely allows.
Report sentences come from templates tied to what was measured. No model call means no server, no API key, and no chance of a fluent sentence that the numbers do not support.
Everything below is recorded per rep, so a set is not a single score but a trace you can look back through.
When a set ends you are two metres from the phone, not holding it. So the result arrives in three layers instead of one screen you would have to walk over to read.
Illustrative figures — a real set fills these from your own reps.
The easiest way to look accurate is to count everything and stay quiet about the frames you could not read. AMC does the opposite: when a check cannot be made, it says which one and why.
Judgment happens on your device, so the video never has to leave it. Here is exactly what does and does not move.
No install, no sign-up, and no personal details are requested — the participant number the app uses is issued by the app itself.