Comparison

Slant Gauge vs Protractor Smart

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

Head to head
About

Slant Gauge

Measure angles and slopes with a simple digital display that rotates for easy viewing. This tool speaks the angle aloud, aiding in adjustment work. Calibration can improve its accuracy.

Highlights
  • Simple angle and slope measurement
  • Spoken angle output
  • Digital display rotates for visibility
  • Calibration for improved accuracy
  • Useful for adjustment work
Features
Read full description

* A professional also uses at work. ・Simple measurement of an angle and a slope can be performed. ・An angle is spoken. It is helpful by adjustment work. ・If a calibration is carried out, accuracy will become good more. ・The digital display of an angle and a slope rotates so that it may be easy to be visible in accordance with inclination.

About

Protractor Smart

This app acts as a smart instrument for measuring angles using your device's camera. It offers two free modes for measuring angles on screen or using a plumb bob for slopes, with an additional premium mode for polygon measurements.

Highlights
  • Camera-based angle measurement
  • Touch measure mode
  • Plumb bob measure for slopes
  • Polygon measurement (premium)
  • Screenshot functionality
Features
Read full description

Protractor - smart instrument to measure angles. Turn on the camera mode and measure the angle of buildings, mountains, or any other object around you. This app includes two free measuring modes: - Touch measure - touch the screen to set the angle (use camera view!). - Plumb bob measure - pendulum - use to determine the slope (remember to calibrate the plumb). In each mode, you can switch to camera view and take measurements of all objects around you. Additional Premium mode: Polygon measurement lets you draw any shape on your screen to check all its angles. Turn on the camera to see the real object through your phone and copy its shape. You can also pick a photo from your gallery or take a new picture to draw a shape on the image. In Premium mode, you can change colors, add helper lines, and switch between different angle units. All modes allows you to make a screenshot of anything on the screen. Enjoy !!!

Screenshots

Slant Gauge4 screens
Protractor Smart4 screens

Verdict

The call

The clearest difference is ads: Protractor Smart at none against Slant Gauge's shown. Slant Gauge's advantage is update cadence (every 3 months vs every 21 months) and review sentiment (62% vs 44%). On price, in-app purchases, monetization model and device support there is nothing between them.

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

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. Slant Gauge sells 1 one-off in-app purchase and Protractor Smart sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.

UpkeepUpdate frequency

Slant Gauge ships an update every 3 months, Protractor Smart every 21 months. The most recent releases landed on October 15, 2026 and October 24, 2026 respectively.

Scorecard3 real differences · 7 level
Slant Gauge versus Protractor Smart: the parameters behind the verdict, then further details
ParameterSlant GaugeProtractor Smart
PriceFreeFree
Rating—4.6 (246 ratings) — better
Positive reviews62.0% of reviews — better43.6% of reviews
Number of ratings—246 — better
Update frequencyEvery 3 months — betterEvery 21 months
AdsYesNo — better
In-app purchasesYesYes
MonetizationFree with in-app purchasesFree with in-app purchases
DevicesiPhone, iPodiPhone, iPad, iPod — better
Requires iOS15.614.0 — better
Further details — not scored
Size22 MB11 MB
Age rating4+4+
DeveloperIsamu SakamotoExaMobile S.A.

Customer experience

Slant Gauge

Written reviews50 reviews
Positive62.0%
Neutral12.0%
Negative26.0%

Protractor Smart

All ratings242 ratings
Positive91.3%
Neutral1.7%
Negative7.0%
Written reviews55 reviews
Positive43.6%
Neutral5.5%
Negative50.9%

Bugs and requests

Slant Gauge

Not enough reviews yet to summarise bugs or requests.

Protractor Smart

Reported bugs

8 issues
  • App loads indefinitely
  • App does not launch after iOS updates
  • Stuck on loading screen
  • Photo upload not possible in premium version
  • Upside-down protractor on iOS
Show 3 more
  • Phone locks during use
  • Camera mode is terrible and inaccurate
  • Poor calibration

Requested features

6 requests
  • Improve camera function (light, zoom)
  • Add automatic hold function
  • Increase digital readout size
  • Add more skins/cosmetics
  • Option to remove ads
Show 1 more
  • Fix upside-down protractor on iOS

In-app purchases

1 purchases

Slant Gauge

One-time1
  • 角度傾斜計$1.99
1 purchases

Protractor Smart

One-time1
  • AdBlock - Remove ads$1.99

Questions

Is Slant Gauge free?
Slant Gauge is free to download, with in-app purchases available.
Is Protractor Smart free?
Protractor Smart is free to download, with in-app purchases available.
Do Slant Gauge or Protractor Smart have ads?
Slant Gauge shows ads; Protractor Smart does not.
Which is updated more often, Slant Gauge or Protractor Smart?
Slant Gauge ships an update every 3 months, and Protractor Smart every 21 months. Most recently, Slant Gauge was updated on October 15, 2026 and Protractor Smart on October 24, 2026.

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