Weigh-ins · Trend line · Progress photos

The free weight tracker for iPhone that shows your real trend

Log your weight in seconds, add progress photos and see your real trend, weekly rate and BMI. Weigh-ins and photos stay on your iPhone.

Download on the App Store
  • Free, no ads
  • Weigh-ins stay on your iPhone
  • Works with Apple Health
Periscope home screen showing current weight, average change per week and a monthly weight chart

Trend line

See your weight trend, not the daily noise

Water and salt can move the scale a kilo overnight. The trend line smooths that out, so you can see which way you're really heading.

Six weeks of sample weigh-ins: noisy dots, steady trend.

How trend weight works →Try it with your own numbers →
Illustrative data
7980818283
Daily weigh-inTrend line
Trend weight
80.1 kg
Weekly rate
−0.5 kg
Biggest daily swing
1.1 kg

Inside the app

How it works, screen by screen

Periscope home screen with current weight, entries, average per week and a weight chart

01 / 05

Log your weight in seconds

Tap +, enter your weight, done. Add a note or up to two photos if you like.

Progress photos

Drag to compare

It works just like the slider in the app. Your own photos stay on your iPhone.

How to take progress photos that show change →
Before
After

Sample photos from Periscope's demo entries.

Also in the app

Small things that make tracking easier

  • Goal weight

    A goal line in your reports and a goal widget.

  • BMI tracker

    BMI from your trend weight in every report.

  • Widgets

    Trend, monthly, stats and goal widgets, Lock Screen too.

  • Apple Health

    Smart-scale weigh-ins import when you open the app.

  • Weigh-in reminders

    Daily, every three days or weekly.

  • Face ID lock

    Keep your weigh-ins and photos behind Face ID.

  • kg or lbs

    kg or lbs, cm or ft/in, plus notes.

  • 8 languages

    English, Spanish, French, German, Italian, Portuguese, Japanese and Chinese.

Privacy

Your weigh-ins stay on your iPhone

On your iPhone

Weigh-ins, photos and Apple Health data are stored on your phone, not uploaded.

Sign in with Apple

Your account holds only sign-in details. Delete it any time and your data goes with it.

Analytics without your numbers

Basic usage analytics never include your weight, photos or measurements.

Read the privacy policy →

Frequently asked questions

Is Periscope a weight loss app?

It's a weight tracker. A trend line, reports with BMI and progress photos show whether your weight is really going down. Use it on its own or with any diet.

Is Periscope really free?

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

Can I track my BMI?

Yes. Add your height and every report shows your BMI, calculated from your trend weight.

Does it work with my smart scale?

Yes, if it saves to Apple Health. Periscope reads your weight when you open the app and never writes to Health.

Where is my data stored?

Weigh-ins, notes and photos stay on your iPhone. Our server only holds your Sign in with Apple account.

How is the trend line calculated?

It's a lag-corrected moving average (double exponential smoothing), calculated daily with missing days filled in.

Which iPhones does it work on?

iOS 15.1 or later. Widgets need iOS 17.

Which languages does Periscope support?

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

Learn and free tools

Short, sourced guides and two free calculators.

Weight trend calculator →

Paste your weigh-ins, get your trend and weekly rate.

BMI calculator →

BMI, category and healthy weight range.

Latest articles

All articles →

Start with today's weigh-in

Free on iPhone.

Download on the App Store

Requires iOS 15.1 or later. Widgets need iOS 17.