Comparison

Protractor Smart vs Bubble Level Tool

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

Head to head
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 !!!

About

Bubble Level Tool

Measure precise angles and levels with your device. Easily switch between portrait, landscape, and surface level modes. Lock and reset angles for accurate measurements.

Highlights
  • Measure current device angle
  • Reset angle
  • Lock angle
  • Portrait mode
  • Landscape mode
  • Surface level
Read full description

Bubble Level Tool - Digital lets you see the current angle of your device, along with reseting and locking the angle too. Tilt the device to measure the precise angle and easily switch between portrait, landscape & surface level. If you have any questions or feedback, I'm all ears. Bubble Level Tool - Digital was created by an individual in his free time, and I’d love to know what you think. I’m available through Twitter @elohohel & Mastodon @elohohel@mastodon.social. Terms of Use (EULA) - https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ A subscription / purchase is required to continue using the app.

Screenshots

Protractor Smart4 screens
Bubble Level Tool4 screens

Verdict

The call

Protractor Smart and Bubble Level Tool both sit at 4.6 stars, but that hides the real split: 44% of Protractor Smart's written reviews are positive against 6% of Bubble Level Tool's. Protractor Smart also leads on monetization model (free with in-app purchases vs subscription). Bubble Level Tool's advantage is update cadence (weekly vs every 21 months) and ratings volume (2.5K vs 242). On price, rating, ads and in-app purchases 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. Protractor Smart sells 1 one-off in-app purchase and Bubble Level Tool sells 9 in-app purchases, starting at $3.99 per 7 days. Whichever you choose, the download price is not the number that matters.

ReceptionRating · Positive reviews · Number of ratings

Protractor Smart holds the better App Store score, 4.6 against 4.4. That said, the two scores are not equally well evidenced: Bubble Level Tool has 2.5K ratings behind it against 242, so its average is the more settled of the two. Written reviews point the same way: 44% of Protractor Smart's written reviews are positive against 6% of Bubble Level Tool's.

UpkeepUpdate frequency

Protractor Smart ships an update every 21 months, Bubble Level Tool weekly. Both last shipped on October 13, 2026.

Scorecard4 real differences · 6 level
Protractor Smart versus Bubble Level Tool: the parameters behind the verdict, then further details
ParameterProtractor SmartBubble Level Tool
PriceFreeFree
Rating4.6 (242 ratings) — better4.4 (2.5K ratings)
Positive reviews43.6% of reviews — better5.9% of reviews
Number of ratings2422.5K — better
Update frequencyEvery 21 monthsWeekly — better
AdsNoNo
In-app purchasesYesYes
MonetizationFree with in-app purchases — betterSubscription
DevicesiPhone, iPad, iPod — betteriPhone, iPod
Requires iOS14.0 — better15.0
Further details — not scored
Size11 MB5 MB
Age rating4+4+
DeveloperExaMobile S.A.Rihab Mehboob

Customer experience

Protractor Smart

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

Bubble Level Tool

All ratings2,466 ratings
Positive84.6%
Neutral2.4%
Negative13.0%
Written reviews135 reviews
Positive5.9%
Neutral0.0%
Negative94.1%

User reviews

Protractor Smart

From 242 App Store ratings

What we love

  • 👍 Useful for measurements
  • 👍 Accurate for its purpose
  • 👍 Convenient and handy
  • 👍 Good for specific tasks (e.g., knife sharpening, stereo mic angles)
  • 👍 No excessive charges

Room to improve

  • 🐛 App freezes/loads indefinitely
  • 🐛 Does not launch after updates
  • 🐛 Stuck on loading screen
  • 🐛 Inaccurate or unstable measurements
  • 🐛 Camera quality issues

Bubble Level Tool

From 2.5K App Store ratings

What we love

  • ⭐️ Useful app
  • 🤠 Handy when needed
  • 👍 It simply works

Room to improve

  • 💰 Expensive subscription
  • 🚫 Unusable without paying
  • 📢 Constant upsell pop-ups
  • 🕰️ Limited free trial
  • 🤯 Frustrating experience

Bugs and 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

Bubble Level Tool

Reported bugs

2 issues
  • Inaccurate level readings
  • Compatibility issues with older devices

Requested features

3 requests
  • Percentage slope display option
  • Ability to switch between degree and percent
  • Refund/cancellation options

In-app purchases

1 purchases

Protractor Smart

One-time1
  • AdBlock - Remove ads$1.99
9 purchases

Bubble Level Tool

Subscriptions7
  • Bubble 1 Week$3.997 Days
  • Bubble 1 Week$4.997 Days
  • Bubble 1 Month3 Days trial$5.991 Month
Show 4 more
  • Bubble 1 Month$9.991 Month
  • Bubble 1 Year3 Days trial$24.991 Year
  • Bubble 6 Months$29.996 Months
  • Bubble 1 Year3 Days trial$39.991 Year
One-time2
  • Bubble Lifetime$17.99
  • Bubble Lifetime$69.99

Questions

Is Protractor Smart free?
Protractor Smart is free to download, with in-app purchases available.
Is Bubble Level Tool free?
Bubble Level Tool is free to download, with in-app purchases available.
Which has better reviews, Protractor Smart or Bubble Level Tool?
Protractor Smart is rated higher. Protractor Smart averages 4.6 out of 5 from 242 ratings, while Bubble Level Tool averages 4.4 from 2.5K ratings.
Do Protractor Smart or Bubble Level Tool have ads?
Neither Protractor Smart nor Bubble Level Tool shows ads.
Which is updated more often, Protractor Smart or Bubble Level Tool?
Protractor Smart ships an update every 21 months, and Bubble Level Tool weekly. Most recently, Protractor Smart was updated on October 13, 2026 and Bubble Level Tool on October 13, 2026.

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