Pentatone vs FrobulatorAU
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Pentatone
This music app offers a unique pentatonic keyboard and built-in synthesizer, inspired by instruments like the kora and mbira. It features a sophisticated scale selection system and is optimized for touchscreen devices, providing an expressive and easy-to-play musical experience.
- Easy-to-play 'strummable' pentatonic keyboard
- 9 selectable pentatonic scales
- Custom FM synthesizer engine
- 25 preset sounds with macro controls
- Polyphonic touch and aftertouch response
- AUv3 functionality for host apps
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"Beautiful, fun and inspiringly expressive" - The Arithmophone Pentatone is a music app featuring an easy to play pentatonic keyboard and a built-in synthesizer. Instead of using piano keys or a grid-based interface, Pentatone takes a fresh approach, optimised for the ergonomics of touchscreen devices and inspired by instruments like the kora and mbira. The app also has a sophisticated scale selection system that includes all the common pentatonic scale types and unlocks some more unusual ones. Pentatone features: - An easy-to-play and 'strummable' keyboard, split for two handed playing - An original pentatonic scale system with 9 selectable scales, in just intonation or standard tuning - A custom synth engine (binaural 2x2 op FM with stereo detune, resonant filter, delay and reverb) - 25 preset sounds with macro sliders for tone and ambience - Initial touch and aftertouch response, both polyphonic - AUv3 functionality for use within host apps like GarageBand, Koala Sampler and Loopy Pro Pentatone user feedback: "Amazing! Love the simple UI and the musical keyboard. Also the sounds are lovely!" "This is very cool - beautiful interface and instantly musical." "This really is a joy to play and the tones are really expressive in fun ways that invite different types of creativity." "This app is such a brilliant idea!" "This is amazing. So fun to play. So easy to play with my daughter and my niece. The tones are wonderful." "This is an inspiringly expressive instrument! Really a joy to interact with." "This thing is AWESOME! It’s so easy to make up new stuff with it!" *** Pentatone is part of the Arithmophone project An Arithmophone is a thing that turns numbers into sounds, or math into music. Its name is derived from the ancient Greek words arithmos (number) and phone (sound). Any iPhone or iPad is itself an Arithmophone, because it routinely turns lists of binary numbers into sounds, for example when you use it to listen to music. But this app is a bit more 'arithmophonic' still, because it takes pure and simple harmonic ratios like 3:2 and 5:4 and uses these to build musical scales. You can use it as an easy-to-play instrument, a source of melodic and harmonic inspiration or a tool for learning about music and exploring the deep connection it has with numbers. Keep an eye out, future plans for the Arithmophone on iOS include: - PENTATONE JR., a simplified and text-free version of Pentatone, optimized for young/beginning musicians - DIATONE, the diatonic companion to Pentatone, featuring a 7-note-per-octave keyboard with all the familiar major and minor scales and modes - MIDI / MPE versions of Pentatone and Diatone - TONEHIVE, a microtonal keyboard synth for 7 limit just intonation - HUYGENS, a microtonal keyboard synth for 31 EDO To stay posted, join the community at reddit.com/r/arithmophone or subscribe to the Arithmophone youtube channel: https://www.youtube.com/@arithmophone
FrobulatorAU
This audio effect plugin transforms sounds with spectral delay, adding unique character to music projects. It's a free and open-source tool designed for use in various audio applications, offering extensive creative possibilities.
- Spectral delay effect
- AUv3 plugin
- Use in GarageBand, AUM, and other DAWs
- Multiple instances per project
- Free and open-source
- No ads or in-app purchases
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Venerable inter-app audio effect Frobulator reborn — at long last — as an AUv3 plugin. Use it in GarageBand, AUM or your favourite audio application. Add multiple instances in the same project. Drag your frobulation kicking and screaming into the 21st century. Frobulator is a spectral delay effect. It makes your noises a little bit stranger. Twiddle the knobs to find something you like, or don't and throw it away. No-one will hold it against you. Frobulator is free as in beer and free as in speech. Freer, probably, given the state of both those things these days. No ads, no in-app purchases, no subscriptions, no surveillance, no nag screens. If you happen to be one of the 6 people who asked for this, rejoice! If you aren't, now's your chance to discover what you've been missing all this time. Or not. I'm not the boss of you.
Screenshots
Verdict
The clearest difference is update cadence: FrobulatorAU at every 9 days against Pentatone's every 5 weeks. Pentatone's advantage is iOS requirement (15.6 vs 17.0). On price, rating, ratings volume and ads 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. Neither carries in-app purchases, so what you see is what you pay.
On the App Store both sit at effectively the same score — 5.0 for Pentatone against 5.0 for FrobulatorAU. Both are backed by a comparable volume of ratings — 15 and 8 respectively.
Pentatone ships an update every 5 weeks, FrobulatorAU every 9 days. The most recent releases landed on November 5, 2026 and October 31, 2026 respectively.
| Parameter | Pentatone | FrobulatorAU |
|---|---|---|
| Price | Free | Free |
| Rating | 5.0 (15 ratings) | 5.0 (8 ratings) |
| Positive reviews | 100.0% of reviews | — |
| Number of ratings | 15 — better | 8 |
| Update frequency | Every 5 weeks | Every 9 days — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free | Free |
| Devices | iPhone, iPad, iPod — better | iPhone, iPad |
| Requires iOS | 15.6 — better | 17.0 |
| Further details — not scored | ||
| Size | 16 MB | 2 MB |
| Age rating | 4+ | 4+ |
| Developer | Chiel Zwinkels | Matthew Caldwell |
Customer experience
Pentatone
FrobulatorAU
In-app purchases
Pentatone
No in-app purchases
FrobulatorAU
No in-app purchases









