Comparison

Hinge Protractor vs FoldMetry

Price, ratings, monetisation and update history for both apps, side by side β€” with what reviewers say about each.

Head to head
About

Hinge Protractor

Features
Read full description

Hinge Protractor for iPhone Duo: Forgot your protractor to school? Want a measure an angle at construction? Tracing a pattern and need a glowing guide line under the paper? Use the app on Duo! On iPhone Duo, it reads the hinge sensor and shows the exact angle between the two screens as you fold. On any other iPhone, the whole screen becomes a ruler at true physical size. FEATURES: - Live angle: Fold or tilt and watch the number follow in real time. - Resizable measurements: Pinch, twist and drag the reading anywhere on screen. - Honest precision: one-time calibration: open and close the hinge slowly, once. - Real-size ruler: Rulers along the screen edges show true physical size in centimetres or inches. Check them against any bank card for perfect accuracy. - Relative measurments: Drag two lines across the screen and read the exact position off both rulers. - Saved measurements: Double-tap to save an angle, a ruler position or both. Add a note, drag to reorder, and undo with one tap. - Configuration: Degrees or radians, centimeters or inches, light or dark theme, in English, Russian or Chinese.

About

FoldMetry

Features
Read full description

Open your iPhone Duo. See the angle at a glance. FoldMetry puts the current hinge angle front and center. The number moves as your device opens and closes, with a clean display that stays out of your way. Have a position in mind? Set a target angle and feel a gentle tap when you reach it. Save more than one for the angles you use often. The app follows your device’s Light or Dark appearance, and measurements stay on your device. All measuring features are free. If FoldMetry earns a spot in your day, you can leave a one-time tip to support its independent development. Tips don’t unlock extra features. Hinge angle measurement is available only on iPhone Duo. Other iPhones and iPad can view device support information but cannot measure hinge angles.

Screenshots

Hinge Protractor4 screens

Verdict

The call

The clearest difference is in-app purchases: Hinge Protractor at none against FoldMetry's 1. FoldMetry's advantage is update cadence (every 6 days vs fortnightly). On price, ads, device support and iOS requirement there is nothing between them.

Scored on Price Β· Rating Β· Positive reviews Β· Number of ratings Β· Update frequency Β· Ads Β· In-app purchases Β· Monetization Β· Best chart rank Β· Devices Β· Requires iOS

CostPrice Β· In-app purchases Β· Ads Β· Monetization

Both are free to download. FoldMetry sells 1 one-off in-app purchase. Hinge Protractor asks for nothing beyond the download.

UpkeepUpdate frequency

Hinge Protractor ships an update fortnightly, FoldMetry every 6 days. The most recent releases landed on October 31, 2026 and November 1, 2026 respectively.

Scorecard2 real differences Β· 4 level
Hinge Protractor versus FoldMetry: the parameters behind the verdict, then further details
ParameterHinge ProtractorFoldMetry
PriceFreeFree
Update frequencyFortnightlyEvery 6 days β€” better
AdsNoNo
In-app purchasesNo β€” betterYes
DevicesiPhone, iPad, Mac β€” betteriPhone, iPad
Requires iOS26.0 β€” better27.1
Further details β€” not scored
Size6 MB5 MB
Age rating4+4+
DeveloperMaksim TatarchenkovδΊšε†› 胑

In-app purchases

None

Hinge Protractor

No in-app purchases

1 purchases

FoldMetry

One-time1
  • Optional Developer Support$0.99

Questions

Is Hinge Protractor free?
Hinge Protractor is free to download, with no in-app purchases.
Is FoldMetry free?
FoldMetry is free to download, with in-app purchases available.
Do Hinge Protractor or FoldMetry have ads?
Neither Hinge Protractor nor FoldMetry shows ads.
Which is updated more often, Hinge Protractor or FoldMetry?
Hinge Protractor ships an update fortnightly, and FoldMetry every 6 days. Most recently, Hinge Protractor was updated on October 31, 2026 and FoldMetry on November 1, 2026.

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