I’ve thought about similar apps, and gave up on the end because allergies were to complex to surface through logging. What type of allergies and tracking were you working on?

The most common ones in food and the most common ones in the air. Our idea was to track how people react, compile a log and have it processed so that we can tell them - yup you have this one allergy because of this pattern of what you ate, did, the air you breath etc. based on the evidence submitted. It was a very long "LOG" but if people were serious about compiling it and didn't l eave things blank, the folks on our med team were certain we could have given them a "cure" that worked for their allergy.

Ofc, this wouldn't work with super extreme cases where you're allergic to a very specific uncommon thing. but this is a 80/20 solution.

Thanks for that. In my case I suffered guessing and tracking for years before I gave in and had extensive tests done. As for cures, that’s another story.