Voice Spectrogram Logger vs Mandel Draw
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Voice Spectrogram Logger
Visualize voice frequencies in a spectrogram from 20-2500Hz. Adjust display with sliders and log recordings to export as PNG files. Functions fully offline and supports background processing.
- Real-time voice spectrogram display
- Adjustable frequency range (20-2500Hz)
- Zoomable spectrogram with pinch gestures
- Customizable spectrogram gradation
- Logging mode with history export
- Offline functionality
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1. DESPLAY The spectrogram of voice is displayed in the range of 20 - 2500Hz. You can zoom in/out the spectrogram by pinching in/out smoothly. Also landscape orientation is supported. 2. USEFUL By moving "vivid" slider, the gradation of spectrogram is controlled. The gradation is also controlled by moving "baseline" slider in "Setting" tab and selecting "Mean" or "RMS" as the way of smoothing the spectrogram out. 3. LOGGING When "log" switch is ON, this app runs in the logging mode. To choose a past log from "History" tab, you can pull it from iPhone via email as a PNG file. 4. AVAILABLE Without cellular data service, the full functions are available. The background processing is supported. 5. TECHNICAL NOTE Sample rate: 44.1kHz Bit depth: 32bit float FFT window function: Blackman FFT samples: 4096
Mandel Draw
Explore the infinite beauty of fractals with this intuitive drawing app. Generate Mandelbrot and Julia sets with numerous functions and color palettes. Enjoy simple touch controls for navigation and advanced settings for high-resolution output and iCloud syncing.
- Mandelbrot and Julia set generation
- 80+ fractal functions
- 20+ color palettes
- Intuitive touch controls (drag, pinch, tap)
- High-resolution output
- iCloud Sync for favorites and palettes
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Mandel Draw is an application that allows you to enjoy fractals, Mandelbrot sets and filled Julia sets, in a fast and comfortable way. The app allows you to draw an infinite number of fractal images from up to 80 different functions, 20+α color palettes, and freely configurable Julia parameters. Operation is simple. Drag to move, pinch to zoom in and out. Double- and triple-tap operations are also available. Convenient settings are also available. - Use DF64 operation: Double the float operation to make it possible to zoom in more. (Disabled in the Appendix 1,2) - Select render version: Two types of rendering methods can be selected. - Display coordinates and magnification: The current coordinates and magnification will be displayed on the screen. - Output detailed information: Add detailed information to the text when sharing. - High-resolution output: Outputs at 4 times the vertical and horizontal resolution when sharing. - iCloud Sync: Share favorites and My Palette with another iPhone or iPad. In addition, all functions are available when unlocked with in-app purchase. 1) All functions are selectable 2) All palettes can be selected 3) Up to 2000 favorites can be saved 4) Maximum number of My Palettes that can be saved is now 30. Now, please enjoy the wonderful and mysterious world of fractals. What is a fractal? Simply put, a fractal is a self-similar figure that does not lose its complexity no matter how much it is enlarged. (Though computers have their limitations.) There are various fractal shapes, such as the Koch curve, Sierpinski's gasket, and Menger's sponge. The Mandelbrot set and the filled Julia set are fractals drawn computationally on the complex plane.
Screenshots
Verdict
The clearest difference is review sentiment: Mandel Draw at 53% against Voice Spectrogram Logger's 0%. Mandel Draw also leads on rating (4.5 vs 1.0) and update cadence (weekly vs every 15 months). Voice Spectrogram Logger's advantage is monetization model (free vs free with in-app purchases). On price, 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
Both are free to download. Voice Spectrogram Logger sells 1 one-off in-app purchase and Mandel Draw sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.
Mandel Draw holds the better App Store score, 4.5 against 1.0. That said, the two scores are not equally well evidenced: Mandel Draw has 147 ratings behind it against 1, so its average is the more settled of the two. Written reviews point the same way: 0% of Voice Spectrogram Logger's written reviews are positive against 53% of Mandel Draw's.
Voice Spectrogram Logger ships an update every 15 months, Mandel Draw weekly. The most recent releases landed on October 2, 2026 and October 14, 2026 respectively.
| Parameter | Voice Spectrogram Logger | Mandel Draw |
|---|---|---|
| Price | Free | Free |
| Rating | 1.0 (1 ratings) | 4.5 (147 ratings) — better |
| Positive reviews | 0.0% of reviews | 53.3% of reviews — better |
| Number of ratings | 1 | 147 — better |
| Update frequency | Every 15 months | Weekly — better |
| Ads | No | No |
| In-app purchases | Yes | Yes |
| Monetization | Free — better | Free with in-app purchases |
| Devices | iPhone, iPad, iPod — better | iPhone, iPad |
| Requires iOS | 15.5 — better | 16.0 |
| Further details — not scored | ||
| Size | 7 MB | 22 MB |
| Age rating | 12+ | 4+ |
| Developer | Yukiko Iwai | Kouji Mori |
Customer experience
Voice Spectrogram Logger
Mandel Draw
In-app purchases
Voice Spectrogram Logger
- Remove Ads$3.99
Mandel Draw
- Unlock$1.99
Questions
Is Voice Spectrogram Logger free?
Is Mandel Draw free?
Which has better reviews, Voice Spectrogram Logger or Mandel Draw?
Do Voice Spectrogram Logger or Mandel Draw have ads?
Which is updated more often, Voice Spectrogram Logger or Mandel Draw?
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