I built recovery-trail, a small local-first Apple Health viewer that answers one specific training question:

Should I push today, or should I pull back?

The part I like most is what it does not use.

There is no backend. There is no account. There is no upload. There is no LLM reading your health data and inventing a confident-sounding paragraph.

It is just a browser app, a web worker, some trend math, and a rule trace.