Comparison

Decibel Meter Plus Pro vs Smart Protractor & Angle Meter

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

Head to head
About

Decibel Meter Plus Pro

Measure the sound levels around you with this utility app. It displays average, peak, and max values, offers decibel exposure time guidelines, and provides information on noise-induced hearing loss. The app also allows data recording and export for analysis.

Highlights
  • Measure sound levels
  • Display average, peak, and max values
  • Decibel exposure time guidelines
  • Information on noise-induced hearing loss
  • Record and export data
  • Calibrate measurements
  • Universal app support
Features
Currently charting
Read full description

Decibel Meter Plus Pro turns your iPhone or iPad into a clean and easy-to-use sound level meter. Measure the noise around you in real time, view current, average, max, and peak dB readings, save measurement sessions, and export reports when you need to keep a record. Whether you want to check a quiet room, monitor everyday environmental noise, compare sound levels over time, or save a simple noise report, Decibel Meter Plus Pro gives you a clear and modern way to do it. KEY FEATURES • Real-time decibel meter View live sound levels with a large, easy-to-read meter. • Current, average, max, and peak values Quickly understand how sound levels change during a measurement session. • Live noise trend See noise changes over time instead of relying on a single number. • Save measurement sessions Keep useful sound level records for later review. • Session history Browse saved sessions with date, duration, average level, max level, and noise category. • Session reports Review key sound level stats, noise trend charts, location notes, and report details. • Export & share reports Export saved reports as an image, PDF, or CSV file. A limited number of free report exports is included. Unlock Unlimited Reports with a one-time purchase for unlimited exports. • Optional location saving Save location information only with sessions you manually save. • Calibration Adjust readings to better match a reference sound meter. • Noise level guide Learn common sound levels and tips for better measurements. • iPhone and iPad support Enjoy a redesigned interface that works beautifully on both iPhone and iPad. • 30+ languages The app is now localized for users around the world. • Privacy-friendly design Audio is processed on your device and is not uploaded. UNLIMITED REPORTS Unlimited Reports is an optional one-time unlock for users who want unlimited image, PDF, and CSV report exports. No subscription is required. SUPPORT If you have questions, feedback, or need help with purchases or report exports, please contact us at: ipixeltech@gmail.com IMPORTANT NOTE Decibel Meter Plus Pro uses the built-in microphone on your device. Readings are intended for general reference and everyday noise checks. For certified workplace testing, legal compliance, or professional acoustic measurement, please use certified sound level equipment.

About

Smart Protractor & Angle Meter

Features
Read full description

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

Screenshots

Decibel Meter Plus Pro4 screens
Smart Protractor & Angle Meter4 screens

Verdict

The call

The clearest difference is price: Smart Protractor & Angle Meter at Free against Decibel Meter Plus Pro's $2.99. Decibel Meter Plus Pro's advantage is chart position (#164 vs unranked) and iOS requirement (15.0 vs 17.6). On update cadence, ads, in-app purchases 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

Smart Protractor & Angle Meter is free to download; Decibel Meter Plus Pro costs $2.99 up front. Decibel Meter Plus Pro sells 1 one-off in-app purchase and Smart Protractor & Angle Meter sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.

UpkeepUpdate frequency

Decibel Meter Plus Pro ships an update every 2 months, Smart Protractor & Angle Meter every 6 weeks. Both last shipped on October 14, 2026.

Scorecard3 real differences · 8 level
Decibel Meter Plus Pro versus Smart Protractor & Angle Meter: the parameters behind the verdict, then further details
ParameterDecibel Meter Plus ProSmart Protractor & Angle Meter
Price$2.99Free — better
Rating3.8 (80 ratings) — better—
Positive reviews52.4% of reviews—
Number of ratings80 — better—
Update frequencyEvery 2 monthsEvery 6 weeks — better
AdsNoNo
In-app purchasesYesYes
MonetizationPaid—
Best chart rank#164 — better—
DevicesiPhone, iPad, iPod — betteriPhone, iPad
Requires iOS15.0 — better17.6
Further details — not scored
Size12 MB7 MB
Age rating4+4+
Developer华芳 张Vladislav Zhirnov

In-app purchases

1 purchases

Decibel Meter Plus Pro

One-time1
  • Unlimited Reports$4.99
1 purchases

Smart Protractor & Angle Meter

One-time1
  • Full version$2.99

Questions

Is Decibel Meter Plus Pro free?
Decibel Meter Plus Pro costs $2.99, and also offers in-app purchases.
Is Smart Protractor & Angle Meter free?
Smart Protractor & Angle Meter is free to download, with in-app purchases available.
Do Decibel Meter Plus Pro or Smart Protractor & Angle Meter have ads?
Neither Decibel Meter Plus Pro nor Smart Protractor & Angle Meter shows ads.
Which is updated more often, Decibel Meter Plus Pro or Smart Protractor & Angle Meter?
Decibel Meter Plus Pro ships an update every 2 months, and Smart Protractor & Angle Meter every 6 weeks. Most recently, Decibel Meter Plus Pro was updated on October 14, 2026 and Smart Protractor & Angle Meter on October 14, 2026.

Other comparisons