Assay: Honest Calorie Range

Every other calorie app shows one number. That number is a guess dressed as a fact — and when it is wrong, you stop trusting the app. Assay shows the range. Then it plans against the cautious end, so you are never under-planned. HOW IT IS DIFFERENT • A range, not a number. Every estimate carries a band, and the band is on screen. The oil under the plate is invisible; so is the portion under the rice. That uncertainty cannot be removed, so it is shown instead of hidden. • Two kinds of uncertainty, kept apart. Error that repeats in the same direction at every meal is systematic, and it accumulates across a day. Portion noise is random, and it partly cancels out. Adding them the same way gets one of the two wrong. Assay adds systematic error linearly and random error in quadrature — and tells you which one dominates your day. • It says when it cannot tell. A classifier that reports its first guess without looking at the second has invented its own certainty. When two candidates are close in energy, Assay answers. When they are far apart — a salad and a slice of cake — it names both and asks you. One tap and the estimate narrows. • The cost in your life, not in calories. 620 kcal means nothing to anyone. "23 minutes of your evening walk" does — at your pace, not a textbook average. If Assay has not measured your pace yet, it says so instead of quietly using a table. • A date range, not a date. "You will hit your goal in 5 weeks" ignores every uncertainty above it. Assay gives the earliest and the latest day, from your own daily balance. Beyond a year it says so instead of inventing a date. The 7700 kcal-per-kilogram figure is a convention, not a law, so its own ±12% goes into the result. WHAT IT WILL NOT DO • It will not fake a number it did not measure. • It will not send your food log anywhere. The app makes no network requests at all — this is checked on every build, not merely promised. • It will not shame you. There is no streak to break. PRIVACY Photos are classified on your iPhone and never leave it. No account, no analytics, no server. Assay does not connect to Apple Health.