A camera is not a recorder

When students hear that an app uses the camera, the first question is always the same: where do the pictures go? It is a good question, and the answer should be short enough to remember.

In FitForm, the pictures go nowhere. The camera sends each frame to a small program inside the browser. That program finds thirty-three points on your body — shoulders, elbows, hips, knees and so on — and then the frame is deleted. Only the points are used, and only for a few milliseconds.

What leaves the device is a short summary at the end: the movement you chose, how many repetitions you did, how long it lasted and the score. There is no video, no photograph and no sound.

This design has a cost. The team cannot check a session if someone disagrees with the count, because there is nothing to look at. They also cannot collect pictures to improve the AI. They decided that the cost was worth paying, because a school platform that keeps children's video would have to be trusted completely, and nobody should have to trust software completely.

If you want to check this yourself, you can: turn off the internet and train anyway. Everything still works except sending the score.