for iPhone & Apple Watch
Barcode scanning and food search are free here. Most trackers moved them behind a subscription. Calvin does not.
Coming soon to the App Store, for iPhone and Apple Watch.
Point at a packaged food and log it. No paywall, no scan limit.
USDA Branded, with Open Food Facts as a fallback.
Protein, carbs, fat, fiber, sugar and sodium on every entry.
Recents, usuals and common foods are one tap. Copy yesterday's whole log when today is empty.
A smoothed trend line instead of the daily noise the scale gives you.
Maintenance calories are back-calculated from your real weight trend, so imperfect logging self-corrects against the scale.
Reads activity and energy, and imports weigh-ins automatically.
Home and Lock Screen widgets, Shortcuts support, and your data out whenever you want it.
Search, scan a barcode, or pick from what you usually eat at this time of day. Calvin learns your patterns, so the food you want is normally already on screen.
Macros fill in automatically. Adjust servings and you're done.
Daily weight is noisy — water, salt, sleep. Calvin fits a trend line through it and reads your real rate of change.
Then it works backwards to your actual maintenance calories. Log imperfectly and the number still converges, because the scale is the thing being trusted, not your logging.
Steps, active energy and workouts come from Apple Health, so what you burn is folded into the day without double-counting a workout you already logged.
Fitbit, Whoop and Hevy connect directly if you use them.
There is no sign-up and no login. Your food log lives on your phone, not on a server — and Calvin does not sell, share, or advertise against it.
Some features do call a server: AI photo scanning, food and barcode lookups, and the optional Fitbit, Whoop, Hevy and Google Health connections. The privacy policy sets out exactly what each one sends and what is kept.
An optional subscription, with a 3-day free trial. Everything above stays free whether or not you subscribe.
Free to start, no account to make.
Coming soon to the App Store.
Calvin