Thank you, Sam — and seriously, congrats on day 36 after 12 years. That's the harder build by a mile. 👏

You hit the exact thing most people miss: the WHO boundaries look trivial until you actually implement them. The one that got me was rounding — show BMI to one decimal and a 24.95 quietly rounds to 25.0, flipping "normal" to "overweight" right at the edge, so I had to decide whether to categorize on the raw value or the displayed one. And the Asian-Pacific cutoffs (overweight at ≥23) are a whole separate "what do we show vs hide" call.

Sounds like your quit-smoking tracker ran into the same wall — the boundaries are where all the real decisions live. I'd genuinely like to see it; is it public anywhere?