Logging without the camera
Most days you eat something you have eaten before. Swipe up on the scan button for saved meals, yesterday’s dinner and your recent plates — one tap each, with the same editable audit trail as a scan.
Nutrition for iPhone
Your day, measured.
What’s left is the point.
Metron measures your day the way a measuring vessel does. Photograph what you’re about to eat; the vessel fills, and one figure tells you what is left — with every number traced to the food it came from.
Get Metron on the App Store
Free on iPhone · Pro is optional
- No streaks
- No scores
- Photos never stored
- Processed in the EU
Today
990
kcal remaining
1,060 of 2,050
16,266
foods in the reference database
5
reference sources, each named on the row it supplied
24
languages: English, French, German, Dutch, Spanish, Italian, Greek, Portuguese, Czech, Hungarian, Polish, Romanian, Bulgarian, Danish, Finnish, Swedish, Croatian, Lithuanian, Slovak, Slovenian, Estonian, Latvian, Maltese, Irish
0
streaks, scores or advertising SDKs
01 · Photograph, scan or read
Every number traces back to a food.
Point the camera at a plate, a barcode or a nutrition label. The AI names each food and estimates the portion; on an iPhone with LiDAR, Metron also measures the plate’s volume and uses it to check and scale that estimate. The figures come from USDA (Foundation, SR Legacy and Survey), ANSES CIQUAL and Open Food Facts, or from dishes Metron composes out of them — and every row names where it came from.
When a match is uncertain, Metron shows its confidence and asks you to check. A food the databases do not have gets the model’s own estimate instead of nothing — shown as “≈” in muted ink, never in the same weight as a row from a table, so it is never mistaken for a lookup. Correct a weight, or the food itself, and the totals recompute from your correction.
- Chicken breast, grilled 150 g248USDA Foundation
- White rice, cooked 180 g234ANSES CIQUAL
- Broccoli, boiled 90 g31USDA SR Legacy
- House sauceestimated, not from a reference table, 58 kilocaloriesModel’s estimate · no match in the databases
02 · The budget
It starts as a formula and becomes yours.
Every app starts with an equation for how much you burn. Metron starts there too, and says so on the screen. From your first week it begins computing your expenditure from what you logged against what your weight actually did, and leans on that as far as the evidence supports — a little at first, and mostly after about four weeks of logging with regular weigh-ins.
It is a blend, not a switch: the screen says how much of today’s number is yours yet. Log a workout and that day’s budget rises by the part of it your usual week doesn’t already account for.
Week 6
Mostly your own record — the formula still counts a little.
03 · Your cycle
Your month, legible at a glance — if you have one.
Log a period and Metron draws the month as its four phases — menstrual, follicular, ovulatory, luteal — so where you are reads without a word, with the day the next period is expected. Resting metabolism measurably rises in the luteal phase, so the budget does too — by 180 kcal a day, added on the screen rather than cancelled out behind it. Your micronutrients follow the cycle as well: on menstrual days, iron leads the list.
Period dates never leave your iPhone. The server learns the name of the phase, never a date.
Day 21
Luteal
The word the server receives. Never the date.
04 · Micronutrients
Facts, not scores.
Fourteen-day averages of what you logged, against EFSA reference intakes. Averaged over the days you actually logged, never over the fortnight: dividing by fourteen when you logged six measures your logging, not your eating.
A gap names a food that closes it. Metron never suggests a supplement.
And the everyday parts.
Barcodes and labels
Scan a packet’s barcode, or photograph its nutrition panel and Metron reads it. Neither is limited, on any plan.
Training days Pro
Separate training-day and rest-day budgets that redistribute the week without changing its total.
Apple Health
With your permission, Metron can write your meals to Apple Health. Declining blocks nothing.
Your screen, your way Pro
Home-screen widgets, a choice of vessel forms, your own macro split and nutrient watchlist, and a Today screen you arrange yourself.
The same safeguards for everyone
The protein floor, the deficit limits and the age gates apply to everyone, paid or not. Under 18, pregnant or breastfeeding, Metron never sets a deficit: the daily figure covers what you spend, never less.
What it will not do
Nothing rewards a run of days, or punishes a missed one.
- Streaks
- Scores
- Grades on a day
- An “ideal” body-fat range
- Supplements
Where a measurement is imprecise — body composition especially — Metron says how imprecise, and refuses to call a change real when it sits inside the method’s own error. It is not a medical device and gives no diagnosis.
Private by design
Your photographs are not kept.
Photographs
Sent for one request and discarded. Never stored on our servers, never used to train a model. Location data is stripped on your iPhone before it leaves.
Period dates
They stay on your iPhone. There is no cycles table on our server; it learns the name of the phase, never a date.
No trackers
The app has no advertising SDK, no analytics platform, no data broker and no profiling for advertising. This web page loads an advertising measurement tag only if you accept cookies.
In the EU
Belgian-run and EU-hosted; the analysis happens in the EU. Every export and deletion right, free. Read the privacy policy.
Free, at full accuracy. Pro, if you want more.
Free
- Three photo scans in any seven days
- Barcode, label and manual logging, without limit
- The same model, the same databases, the same accuracy
- The budget, measured from your own record as the weeks go by
- Fourteen-day micronutrients, and the cycle phases
- The full diary, and every privacy control
Metron Pro
- Unlimited photo scans
- Training-day and rest-day budgets
- Your own macro split and a micronutrient watchlist
- The body-composition trend, with the method’s own error drawn in
- Home-screen widgets, vessel forms and your own Today layout
A monthly or yearly subscription, priced in the App Store for your country. Cancel whenever you like; your history stays readable.
Pro is precision and personality. Nothing that keeps you safe is ever behind it.
Questions
Is Metron a medical device?
No. It shows nutritional information; it does not diagnose or treat anything, and it is not medical advice. Do not use it to manage a medical condition, and talk to a clinician before a significant change of diet — particularly if you are pregnant or breastfeeding, under 18, or have any history of disordered eating.
Do I need an iPhone with LiDAR?
No. With LiDAR, Metron also measures the plate’s volume and uses it to check the portion estimate; without it, the portion is estimated from the photo alone. Either way you can correct the weight, and the totals follow your correction.
What happens to my photographs?
Each one is sent for a single analysis and discarded — never stored on our servers and never used for training. If a scan fails, the photo stays in memory on your iPhone for ten minutes so you can retry.
What if I don’t track a cycle?
Then nothing depends on one. Cycle tracking is a choice made in the app, and everything else works the same.
Can I use it if I’m under 18?
Metron is not for anyone under 13. From 13 to 17 it never sets a deficit or a weight-loss goal, and the same deficit rule applies to anyone who indicates pregnancy or breastfeeding: the daily figure covers what you spend, never less. Logging works as usual.
What happens if I cancel Pro?
Your whole history stays readable, and everything free carries on at full accuracy.
On Android?
Metron is on iPhone today. Tell us you want it on Android; we count the presses, and nothing about who pressed.