Comparison

Lambda vs Metal Detector 3D Plus

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

Head to head
About

Lambda

This app helps musicians and sound engineers convert between musical notes, frequencies, and wavelengths. It features a dynamic fader, built-in oscillator, and frequency tracker with waveform display. Customize tuning standards and speed of sound for precise audio analysis.

Highlights
  • Convert notes, frequencies, wavelengths
  • Dynamic fader for real-time adjustment
  • Built-in oscillator with waveform
  • Frequency tracker with waveform
  • Customizable tuning standards
  • Adjustable speed of sound
  • Share data via standard methods
Read full description

Musicians and Sound Engineers. Musical Notes and Frequencies and Wavelengths. Now there's an app from dgApps to convert between them all. The app features a sliding fader to dynamically change frequency, wavelength and musical note, with locks to step through standard third octave frequencies or whole musical notes. There's a built in oscillator so you can hear the frequency, and a frequency tracker so the app can tell you the frequency. Both the oscillator and the frequency tracker display the audio waveform. A settings section allows for different tuning standards, and variations in the speed of sound. Lambda can also receive calculated Speed of Sound in Air values from another dgApps app, Cair. Lambda is now a universal app, equally at home on an iPhone as on an iPad. In Split Mode on an iPad device, side by side with Cair, the calculated Speed of Sound in Air is passed in real time to the Lambda app. Lambda allows you to share frequency/wavelength/note data via all the usual sharing methods.

About

Metal Detector 3D Plus

Features
Read full description

Metal Detector enables you to detect metal objects using your iOS devices. You can preview the magnetic field level through a graph and a 3D directional display. Metal Detector measures the magnetic field using the device’s built-in magnetic sensor. The natural magnetic field level (EMF) typically ranges from 25 to 65 µT (microtesla), or 250 mG (milligauss). 1 µT = 10 mG. Any reading above this range may indicate the presence of metal or a change in electromagnetic activity in the area. The magnetic field level increases when metal (such as steel or iron) is near the phone. Magnetic field levels will fluctuate as you move around. You can use this app to find metal objects like electrical wires in walls or iron pipes underground. Metal Detector is most effective at detecting ferromagnetic materials (e.g., iron) and cannot detect non-ferromagnetic materials such as wood, glass, plastic, paper, copper, or aluminum. Features: • Displays device orientation in 3D space using a compass. • 3D magnet icon enlarges as magnetic field strength increases. • Shows maximum detected magnetic field level. • Graph displays magnetic field level over time. • Screenshot functionality with saving to the camera roll. • 3D magnet orientation defaults to magnetic north, like a traditional compass. • Option to reset the maximum magnetic field value. • Sound notification when the maximum magnetic field level is reached. • Option to enable or disable sound notifications. Usage: • Detect metal objects such as electrical wires in walls or buried iron pipes. • Identify objects that may or may not be metal. • Monitor magnetic field level changes in specific areas (e.g., when approaching large metal structures). • Some users believe it may detect paranormal activity (use at your own discretion). • And much more—limited only by your imagination! You can also record your screen for reference: • Go to Settings > Control Center > Customize Controls, then tap the + next to Screen Recording. • Open Control Center. • Tap the Screen Recording icon (circle with a dot inside) to start recording. • The recording begins after a 3-second countdown. • To stop, tap the red status bar or red icon. • The screen recording will be saved in Photos for later viewing. Note: Magnetic field readings may be affected by nearby electronic equipment (TVs, computers, microwaves) due to electromagnetic interference. Thank you for your support! Visit nitrio.com for more great apps for your iOS devices.

Screenshots

Lambda4 screens
Metal Detector 3D Plus4 screens

Verdict

The call

The clearest difference is iOS requirement: Metal Detector 3D Plus at 13.0 against Lambda's 15.6. On price, update cadence, 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

Lambda costs $2.99 and Metal Detector 3D Plus $2.99 up front. Neither carries in-app purchases, so what you see is what you pay.

UpkeepUpdate frequency

Lambda ships an update every 54 months, Metal Detector 3D Plus every 38 months. Both last shipped on October 4, 2026.

Scorecard1 real difference · 9 level
Lambda versus Metal Detector 3D Plus: the parameters behind the verdict, then further details
ParameterLambdaMetal Detector 3D Plus
Price$2.99$2.99
Rating5.0 (1 ratings) — better—
Positive reviews80.0% of reviews—
Number of ratings1 — better—
Update frequencyEvery 54 monthsEvery 38 months — better
AdsNoNo
In-app purchasesNoNo
MonetizationPaid—
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS15.613.0 — better
Further details — not scored
Size6 MB2 MB
Age rating4+4+
DeveloperdgAppsHeng Jia Liang

In-app purchases

None

Lambda

No in-app purchases

None

Metal Detector 3D Plus

No in-app purchases

Questions

Is Lambda free?
Lambda costs $2.99, with no in-app purchases.
Is Metal Detector 3D Plus free?
Metal Detector 3D Plus costs $2.99, with no in-app purchases.
Do Lambda or Metal Detector 3D Plus have ads?
Neither Lambda nor Metal Detector 3D Plus shows ads.
Which is updated more often, Lambda or Metal Detector 3D Plus?
Lambda ships an update every 54 months, and Metal Detector 3D Plus every 38 months. Most recently, Lambda was updated on October 4, 2026 and Metal Detector 3D Plus on October 4, 2026.

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