About Periscope

Key facts

What it is

A weight tracker app with progress photos, a smoothed trend line and reports

Platform

iPhone, iOS 15.1 or later (widgets need iOS 17)

Price

Free. No ads, no subscription, no in-app purchases

Where your data is stored

Weigh-ins, notes, photos and Apple Health readings stay on your iPhone

Account

Sign in with Apple. The server only holds account details

Main features

Weight log (kg or lbs), up to two progress photos per entry, before-and-after slider, trend line, weekly/monthly/yearly reports with BMI, goal weight, Home Screen and Lock Screen widgets, Apple Health sync, weigh-in reminders, Face ID lock

Languages

English, Spanish, French, German, Italian, Brazilian Portuguese, Japanese, Simplified Chinese

Publisher

Avo Labs

App Store name

Weight Loss Tracker: Periscope

Why we built it

Daily weigh-ins are noisy. Water, salt and food can move the scale a kilo overnight, which makes a steady change hard to see and easy to give up on. We wanted a tracker that shows the trend first, keeps progress photos next to the numbers, and doesn't ask for a subscription or send your body measurements to a server.

The name comes from the app's submarine theme: a submarine rises or sinks by adjusting its weight, and a periscope gives it a clearer view of where it's headed.

How the trend line works

Periscope smooths your weigh-ins with a lag-corrected moving average (double exponential smoothing), calculated for each day, with missing days filled in between weigh-ins. Reports show the trend line, your rate of change per week and your BMI from the trend weight.

Not the Twitter app

Periscope the weight tracker isn't related to Periscope, the live-streaming app Twitter closed in 2021.

Contact

Questions, feedback or press: email us at avo.labs.dev@gmail.com.