Comparison

Bubble Level vs Protractor°

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

Head to head
About

Bubble Level

This app acts as a digital tool to measure angles and levels on your phone. It provides precise readings for verticality, flatness, and slopes in various units, helping you achieve accurate results for DIY projects and professional tasks.

Highlights
  • Digital plumb bob for true vertical checks
  • Two-axis surface level for flatness
  • Angle measurement in degrees, percent grade, and roof pitch
  • Hold function to freeze readings
  • Timestamped log of measurements
  • Fine calibration for accuracy
Features
Read full description

A bubble level, plumb bob and angle finder in one app — hold your phone against a wall, post or shelf and read the exact tilt in degrees, percent grade or roof pitch. Most level apps stop at a bubble sliding in a tube. PlumbLine adds the tool the trades actually reach for: a digital plumb bob that swings to the side a wall leans and snaps green at true vertical, a two-axis surface check that tells you which edge sits low, and a calibration step that cancels out a slightly bent case so every later reading is honest. WHAT YOU GET - Know instantly whether a wall, post or door jamb is truly vertical, not just "close enough" - Level a shelf, picture frame or rail on the first try instead of nudging and re-checking - See if a worktop, tile or table is flat on both axes, and exactly which edge to shim - Read any slope three ways — degrees, percent grade, or rise-in-12 roof pitch — with no math - Freeze a reading with Hold, so you can lower the phone and still see the number - Keep a timestamped log of every check, so you can prove what was true when you left the job PERFECT FOR - DIYers hanging frames, shelves, mirrors and curtain rails - Carpenters, tilers and finish trades checking jambs, studs and worktops - Homeowners setting fence posts, gates and decking - Anyone who wants a straight result without carrying a spirit level around WHY NOT JUST USE A POCKET SPIRIT LEVEL? A physical level tells you the bubble is "about" centred. PlumbLine gives you the number — 0.4 degrees of lean, low on the right — plus a pass or fail badge against a tolerance you set yourself, and a saved record afterwards. It is already in your pocket, and it never gets left in the van. PRIVACY Everything runs on the motion sensor already in your device. No account, no ads, no tracking, no internet connection needed. Your readings and saved log stay on your phone. FULL ACCESS PlumbLine Premium unlocks the full toolkit — plumb bob, spirit level, surface check, the angle finder with percent and roof-pitch units, fine calibration, and the saved measurement log. Choose a weekly plan, a yearly plan, or a one-time lifetime purchase. Restore Purchases is always available in Settings. Open PlumbLine, press a long edge of your phone flat against the next wall you were about to eyeball, and see how far off it really is. Not for surveying, aviation or safety-critical alignment. Readings are approximate. Terms of Use (EULA): https://web-levi.web.app/terms Privacy Policy: https://web-levi.web.app/privacy-policy Questions? Contact tphuc.work@gmail.com

About

Protractor°

This app transforms your iPhone Duo into a digital protractor. Measure angles on paper or between surfaces by simply folding the device to match the desired angle and reading the degrees. Save and organize your measurements for later use.

Highlights
  • Measure angles on paper
  • Measure angles between surfaces
  • Uses iPhone Duo's folding hinge
  • Record and save angle readings
  • Organize measurements by date
Features
Read full description

Use your iPhone Duo as a protractor. Fold it to match an angle and read the degrees. Requires iPhone Duo with iOS 27.1 or later. Measurement uses the phone's folding hinge and isn't available on other devices. MEASURE ON PAPER Stand the phone on its bottom edges and line up each edge with a line on the page. Open or close the fold until both edges match. CHECK TWO SURFACES Rest each half of the phone against a surface and fold it to fit the angle where they meet. Read the angle as you adjust it. KEEP YOUR READINGS Tap Record when you're ready. History groups your saved angles by day and shows the time of each reading. Delete individual readings or clear them all. Next time you need a protractor, unfold your phone.

Screenshots

Bubble Level4 screens
Protractor°4 screens

Verdict

The call

The clearest difference is rating: Protractor° at 5.0 against Bubble Level's 1.0. Protractor° also leads on update cadence (every 2 days vs monthly) and monetization model (free vs free with in-app purchases). Bubble Level's advantage is iOS requirement (17.0 vs 26.0). On price, ratings volume, 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. Bubble Level sells 3 in-app purchases, starting at $4.99 per 7 days and Protractor° sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.

ReceptionRating · Positive reviews · Number of ratings

Protractor° holds the better App Store score, 5.0 against 1.0. Both are backed by a comparable volume of ratings — 1 and 1 respectively.

UpkeepUpdate frequency

Bubble Level ships an update monthly, Protractor° every 2 days. Both last shipped on October 31, 2026.

Scorecard4 real differences · 5 level
Bubble Level versus Protractor°: the parameters behind the verdict, then further details
ParameterBubble LevelProtractor°
PriceFreeFree
Rating1.0 (1 ratings)5.0 (1 ratings) — better
Number of ratings11
Update frequencyMonthlyEvery 2 days — better
AdsNoNo
In-app purchasesYesYes
MonetizationFree with in-app purchasesFree — better
DevicesiPhoneiPhone
Requires iOS17.0 — better26.0
Further details — not scored
Size5 MB13 MB
Age rating4+4+
DeveloperPhuc PhamJust2us Pte Ltd

In-app purchases

3 purchases

Bubble Level

Subscriptions2
  • Bubble Gauge Weekly$4.997 Days
  • Slope Finder Yearly$24.991 Year
One-time1
  • Angle Meter, Pay Once$49.99
1 purchases

Protractor°

One-time1
  • Protractor Lifetime Access$3.99

Questions

Is Bubble Level free?
Bubble Level is free to download, with in-app purchases available.
Is Protractor° free?
Protractor° is free to download, with in-app purchases available.
Which has better reviews, Bubble Level or Protractor°?
Protractor° is rated higher. Bubble Level averages 1.0 out of 5 from 1 ratings, while Protractor° averages 5.0 from 1 ratings.
Do Bubble Level or Protractor° have ads?
Neither Bubble Level nor Protractor° shows ads.
Which is updated more often, Bubble Level or Protractor°?
Bubble Level ships an update monthly, and Protractor° every 2 days. Most recently, Bubble Level was updated on October 31, 2026 and Protractor° on October 31, 2026.

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