// REFERENCE

Glossary

Plain-English definitions of 8 tech-tester terms used in our calorie tracker app reviews. MAPE, food database architecture, photo recognition workflows, barcode scanning, freemium pricing, paywalled features, app versioning, and sync.

General

App Version

The release number of an app build, such as 4.1.2, which tells you exactly which edition of a calorie tracker a review describes.

Database

Barcode

A printed product code, usually a 12-digit UPC or 13-digit EAN, that a calorie tracker's scanner reads to find a packaged food's record.

Food Database

The collection of food records, each with a serving size and nutrient values, that a calorie tracker turns your entries into numbers with.

Pricing

Freemium

A pricing model in which an app is free to use indefinitely, with a paid tier that unlocks extra features or raises usage limits.

Paywalled Feature

A feature an app shows you but will not let you use until you pay for its subscription tier.

Accuracy

MAPE

Mean absolute percentage error: the typical size of a tracker's miss on a meal, expressed as a percentage of the meal's true calories.

Photo AI

Photo Recognition

Estimating which foods are on a plate, and how much of each, from a photograph, so a calorie tracker can log the meal.

Platform

Sync Conflict

What happens when two devices hold different versions of the same diary data and the app has to decide which one to keep.