Comparison

Smart Protractor & Angle Meter vs Bubble Level

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

Head to head
About

Smart Protractor & Angle Meter

Features
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SmartProtractor turns your iPhone into a professional angle-measurement toolkit. Whether you're a carpenter setting bevel cuts, an architect verifying site angles, a student solving geometry problems, or a DIY enthusiast leveling shelves and frames — get accurate readings in seconds, no extra hardware required. 4 MEASUREMENT MODES TOUCH PROTRACTOR Drag two colored handles to measure any angle on screen. Switch between 180° and full 360° modes. Enable snap-to-angle for instant exact values at 5°, 10°, 15°, 30°, and 45° increments. Lock any measurement to prevent accidental movement, then export a clean annotated diagram. CAMERA OVERLAY Overlay a live protractor on your camera feed. Aim at any object — a roof truss, door frame, staircase, or mountain ridge — and read the angle in real time. Pause to freeze the frame, fine-tune the arms, and save or share the annotated photo. PHOTO MEASUREMENT Import any photo from your library. The protractor overlays the image automatically, and you can drag it anywhere across the photo to place it exactly where you need. Adjust arms independently, pan and zoom the photo, then export the composite with the angle annotation included. POLYGON TRACING Tap anywhere to place polygon vertices and trace any irregular shape. All interior angles calculate in real time. Tap the first vertex to auto-close the shape and instantly verify the angle sum — triangle = 180°, quadrilateral = 360°, and so on. Load a photo or use the live camera as background to trace real-world objects directly on screen. LEVEL & INCLINOMETER Measure device pitch and roll with the precision of a digital spirit level. Calibrate to any surface, lock the reading, and switch between pitch and roll axes on a precision dial display. WHO USES SMARTPROTRACTOR • Carpenters — bevel angles, miter cuts, and corner joint verification • Architects — field angle checks against drawings and blueprints • Tile setters — irregular corner measurements before cutting • Students — geometry homework and theorem verification • Builders & DIYers — level shelves, frames, decks, and pictures MEASUREMENT FEATURES • Degrees, radians, and slope percentage • Snap-to-angle at 5°, 10°, 15°, 30°, and 45° increments • Lock mode to freeze any reading against accidental touch • Export & Share — save to Photos or send to any app • Copy angle value to clipboard • No ads · No subscriptions · Zero data collection

About

Bubble Level

Features
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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

Screenshots

Smart Protractor & Angle Meter4 screens
Bubble Level4 screens

Verdict

The call

Smart Protractor & Angle Meter and Bubble Level are too close to call on the numbers: across 6 compared parameters — price, update cadence, ads and in-app purchases among them — neither pulls far enough ahead to decide it. What separates them is feature set and interface, not measurable difference.

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. Smart Protractor & Angle Meter sells 1 one-off in-app purchase and Bubble Level sells 3 in-app purchases, starting at $4.99 per 7 days. Whichever you choose, the download price is not the number that matters.

UpkeepUpdate frequency

Smart Protractor & Angle Meter ships an update every 6 weeks, Bubble Level monthly. The most recent releases landed on October 14, 2026 and October 24, 2026 respectively.

ScorecardNo meaningful differences
Smart Protractor & Angle Meter versus Bubble Level: the parameters behind the verdict, then further details
ParameterSmart Protractor & Angle MeterBubble Level
PriceFreeFree
Rating—1.0 (1 ratings) — better
Number of ratings—1 — better
Update frequencyEvery 6 weeksMonthly — better
AdsNoNo
In-app purchasesYesYes
DevicesiPhone, iPad — betteriPhone
Requires iOS17.617.0 — better
Further details — not scored
Size7 MB5 MB
Age rating4+4+
DeveloperVladislav ZhirnovPhuc Pham

In-app purchases

1 purchases

Smart Protractor & Angle Meter

One-time1
  • Full version$2.99
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

Questions

Is Smart Protractor & Angle Meter free?
Smart Protractor & Angle Meter is free to download, with in-app purchases available.
Is Bubble Level free?
Bubble Level is free to download, with in-app purchases available.
Do Smart Protractor & Angle Meter or Bubble Level have ads?
Neither Smart Protractor & Angle Meter nor Bubble Level shows ads.
Which is updated more often, Smart Protractor & Angle Meter or Bubble Level?
Smart Protractor & Angle Meter ships an update every 6 weeks, and Bubble Level monthly. Most recently, Smart Protractor & Angle Meter was updated on October 14, 2026 and Bubble Level on October 24, 2026.

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