● For iPhone

The honest food tracker.

The promise: no account, no ads, no subscriptions.

A food log that lives on your phone and works fully offline. Exportable any time. Yours, forever.

Describe a meal
Eggs ×2~150
Toast 1 slice~80
Coffee with milk~30
Breakfast ~260 kcal
status: in beta, testing now
the sign-up link will land right here.
Sigma’s Today screen: a donut showing about 1,600 calories, the macro split beside it, and the day’s meals listed underneath.
fig. 01 · today, and the day’s split

01 · logging

Two taps, most days.

The foods you eat most sit at the top, and one tap logs a serving. Repeating last night’s dinner is one tap too. After the first week, that is nearly all of your logging.

Say it out loud

“Chicken and rice and a beer.” It estimates each item, on your device, and you keep the ones you meant.

Scan the label

A barcode, a nutrition panel, or a menu. From the camera, or from a screenshot you already have.

Or just a number

Quick add takes bare calories when that is all you know. Refusing to record a guess does not make the day accurate.

Sigma’s food picker: Repeat dinner listing the last few days you ate it, then Frequent, the foods logged most often, each with a plus that logs one serving.
fig. 02 · repeat last night, or tap a regular
Choosing how much: the amount with its unit, quick portions, and the meal it goes to.
fig. 03 · how much, in units you use
Sigma’s Mirror: intake per day, the weight trend, and an energy balance estimate shown as a range.
fig. 04 · the mirror: a range, not a verdict

02 · the numbers

Every number wears a tilde.

A calorie count is approximate in every app, including the expensive ones. The database entry was measured on a different chicken than yours, and nobody logs the oil in the pan. Sigma writes the tilde instead of pretending.

No false precision

Whole calories, grams to a tenth. A reading of 140.262 kcal is arithmetic, not knowledge.

It says where it came from

USDA, a barcode, a label you scanned, a guess from a description, or your own typing. Every row is tagged.

Your correction wins

Fix anything that looks wrong. Fix it once and it stays fixed, for that food, next time.

03 · portions

It knows what a portion is.

Tablespoons, sticks, large eggs, a 12 oz steak. Where a portion genuinely varies, it says so rather than quoting a number to the gram.

Weighed your steak after cooking? Sigma converts it by the published USDA yield, states the percentage on screen, and tells you what the choice implies before you log it: 16 oz cooked is not a 16 oz steak, it is about 22 oz raw. A 37% jump in calories should never be something you have to infer.

04 · the mirror

Observes, never coaches.

It reports patterns in what you already logged, stays quiet when there is not enough data to say anything honest, and never predicts.

Energy balance shows a range, and the range narrows as you log more. When the answer is indistinguishable from zero, it says that instead of picking a number. No app can tell you your maintenance calories to the calorie. Sigma will not pretend to be the one that can.

05 · your data

Bring your history. Take it with you.

There is no account and no server of ours. What you log lives on your phone and syncs through your own private iCloud, which we cannot read.

CSV, both ways

Export your food, weigh-ins and water any time, and import the same file back. That is the test of whether a file is really yours.

Apple Health

Optional and off by default. Turn it on and your intake is visible to every other app on your phone.

Delete all of it

Two taps, gone from the device and your iCloud. Nothing on our side to delete, because there is nothing on our side.

The one thing that leaves your phone: searching for a food sends the words you type to USDA and Open Food Facts, because that is what a lookup is. Nothing about you goes with it. Read the privacy policy.

06 · the deal

Not for everyone. On purpose.

What you get

  • Fast logging, and a library that learns what you eat
  • Honest estimates, labeled as estimates
  • Portions, raw and cooked, stated conventions
  • Widgets, Shortcuts, Siri, and a lock screen readout
  • Your data, in a file you can read

What it will never do

  • Ask you to make an account
  • Set you a goal, or a streak to protect
  • Tell you that you ate too much
  • Show you an ad, or sell what you ate
  • Claim an accuracy it cannot keep

Sigma is not a medical device and gives no dietary advice.