logSPL vs Metal Detector 3D Plus
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
logSPL
This app functions as a sophisticated sound level meter, offering both basic and advanced features for measuring noise. It allows users to adjust update rates, select weighting types, and view historical data and real-time histograms. Calibration is recommended for optimal accuracy.
- Sound level measurement
- Adjustable update rates (fast/slow)
- Weighting options (A, C, Z)
- Min/max value monitoring
- Average value computation (Leq)
- Historical curve with grid
- Real-time histogram
- Dosemetering capabilities
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This App is a full featured sound level meter, designed by a signal processing expert. It is iPhone/iPod/iPad compatible and adapts itself to the actual screen resolutions ("HD", "retina"). It consists in two parts: half top for basic features, half bottom for advanced ones (L95, %D, ...). Half top was thus designed to be extremely easy to use. Only two settings are requested: * select 'fast' or 'slow' update rate, which corresponds to 2 different integration periods * select the type of weighting: A or C or Z (Z meaning roughly: no filtering) These settings are saved when exiting the App. Some tips for weighting: * select A to evaluate the feeling of a person against a noise * select Z to balance an audio system Supports upside-down orientation. The min and max values are monitored and displayed in green in the upper view. An average value (Leq, LAeq, ...) is computed on top of this: the green triangle. Take care that this latter corresponds to the logarithm of the average power and not to the average of logarithm values, which is completely different. Integration time for this average value is: all time since start-up of the App or last reset. To reset these extreme and average values, touch the text named RESET. Bottom view is used to display an historical curve. A grid is visible, with lines every 10dB vertical and 10s horizontal. Half bottom now: * a real-time histogram is displayed on left side * it can compute L%: L95, L50, ... * it can make some dosemetering: for this you need to set threshold, criterion and exchange values. This is for advanced users due to the complexity of underlying concepts As for all sound-meter (at any price, hardware or software), you should calibrate it against a reference in order to achieve best accuracy. For this go to Mic. tab to add or remove a fixed offset to the measured values. Any question ? Click on the Facebook icon !
Metal Detector 3D Plus
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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
Verdict
The clearest difference is update cadence: logSPL at every 4 months against Metal Detector 3D Plus's every 38 months. logSPL also leads on price ($1.99 vs $2.99). Metal Detector 3D Plus's advantage is iOS requirement (13.0 vs 15.2). On 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
logSPL costs $1.99 and Metal Detector 3D Plus $2.99 up front. Neither carries in-app purchases, so what you see is what you pay.
logSPL ships an update every 4 months, Metal Detector 3D Plus every 38 months. The most recent releases landed on October 8, 2026 and October 27, 2026 respectively.
| Parameter | logSPL | Metal Detector 3D Plus |
|---|---|---|
| Price | $1.99 — better | $2.99 |
| Rating | 5.0 (1 ratings) — better | — |
| Positive reviews | 100.0% of reviews | — |
| Number of ratings | 1 — better | — |
| Update frequency | Every 4 months — better | Every 38 months |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Paid | — |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Requires iOS | 15.2 | 13.0 — better |
| Further details — not scored | ||
| Size | 1 MB | 2 MB |
| Age rating | 4+ | 4+ |
| Developer | Fabien Lefebvre | Heng Jia Liang |
In-app purchases
logSPL
No in-app purchases
Metal Detector 3D Plus
No in-app purchases
Questions
Is logSPL free?
Is Metal Detector 3D Plus free?
Do logSPL or Metal Detector 3D Plus have ads?
Which is updated more often, logSPL or Metal Detector 3D Plus?
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