u/Key-Dig-1597

Solo dev, ~1 year on this. The thing I kept getting stuck on: progress photos depend on pose, distance, lighting, time of day, what you're wearing — almost nothing is repeatable, and most people can't even photograph their own back.

So I went the other direction: enter measurements (height, weight, waist, hip, chest, etc.), generate a parametric 3D body, and compare any two moments on the same model. Red = volume up, blue = volume down. No photos, no camera setup, no account. Body data stays on-device.

Stack: SwiftUI, parametric body model, on-device rendering. iOS 18+, iPhone + iPad.

What I'd actually like feedback on:

1. The Compare screen — is the red/blue overlay readable, or does it need a legend / clearer labels?
2. Onboarding — how many measurements should I ask for before generating the first body? Right now I start from height + weight and let people add circumferences later, but I'm not sure that's the right tradeoff.
3. "Past Me" — letting users reconstruct an old body from a questionnaire when they don't have before photos. I'm worried this feels gimmicky. Does it?

Free to download, link in comments to keep the post clean. Happy to answer anything.