ChordMapMidi vs JAX Stereo Tool (AU)
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
ChordMapMidi
This app is a MIDI controller for exploring musical chords and progressions in major and minor keys. It sends note information to other synthesizer apps on your device, making it a portable tool for musicians and educators.
- Explore chords and progressions
- Major and minor keys
- MIDI controller functionality
- Sends note information to synth apps
- Portable music tool
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ChordMapMidi allows you to explore chords and chord progressions in both major and minor keys, one finger tap at a time. Note: ChordMapMidi is a MIDI controller. It doesn't create sound on its own. It sends note information to synthesizer apps you have on your device. ChordMapMidi is useful for songwriters, MIDI musicians, music educators... especially in places where the only instrument you have is the phone in your pocket. Have fun exploring chords and progressions!
JAX Stereo Tool (AU)
This audio processing tool allows users to visually manipulate the stereo image of digital audio. It functions as a mastering effect, enabling real-time adjustment of stereo width and the recovery of mono compatibility. The app includes a correlograph for visual feedback and optimization.
- Visual stereo image manipulation
- Real-time stereo width adjustment
- Mono compatibility recovery
- Integrated correlograph for visual feedback
- Audio Unit (AUv3) plugin format
- System-wide availability
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JAX Stereo Tool is a visual Audio Unit plugin for manipulating the stereo image of digital audio. The distribution app comes with an embedded plug-in (Audio Unit) that is available system-wide when you install the app. You should be able to use it with most supporting host applications. Audio Units are Apple's recommended method for providing shared audio effects for applications and audio editors. You can load the plugin into any host application that supports at least stereophonic audio effect plug-ins (in Audio Unit format - AUv3) with its own user interface. JAX Stereo Tool has its main use as a mastering effect, that allows you to modify the stereo image of your audio by narrowing or widening it in a controlled manner. That is, the stereo output can be continuously adjusted in the basic function of pure mono to very wide stereo. This happens in real time and you can observe the result with the integrated correlograph, controlling and optimizing the audio thanks to this helpful additional visual information. One of the special functions of JAX Stereo Toolis to recover lost mono-compatibility. This technique is conceptually quite simple and effective but somewhat difficult to understand. Please read the manual for further details. The manual is shipped with the app or available on the product website at https://audio.digitster.com
Screenshots
Verdict
The clearest difference is rating: ChordMapMidi at 5.0 against JAX Stereo Tool (AU)'s 4.4. ChordMapMidi also leads on price ($3.99 vs $5.99). JAX Stereo Tool (AU)'s advantage is update cadence (every 11 days vs every 8 months) and review sentiment (80% vs 53%). On ads, in-app purchases and monetization model 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
ChordMapMidi costs $3.99 and JAX Stereo Tool (AU) $5.99 up front. Neither carries in-app purchases, so what you see is what you pay.
ChordMapMidi holds the better App Store score, 5.0 against 4.4. That said, the two scores are not equally well evidenced: JAX Stereo Tool (AU) has 27 ratings behind it against 5, so its average is the more settled of the two. Written reviews complicate that: 53% of ChordMapMidi's written reviews are positive against 80% of JAX Stereo Tool (AU)'s, so the app with the better star average is not the one people write more warmly about.
ChordMapMidi ships an update every 8 months, JAX Stereo Tool (AU) every 11 days. The most recent releases landed on October 9, 2026 and October 12, 2026 respectively.
| Parameter | ChordMapMidi | JAX Stereo Tool (AU) |
|---|---|---|
| Price | $3.99 — better | $5.99 |
| Rating | 5.0 (5 ratings) — better | 4.4 (27 ratings) |
| Positive reviews | 52.9% of reviews | 80.0% of reviews — better |
| Number of ratings | 5 | 27 — better |
| Update frequency | Every 8 months | Every 11 days — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Paid | Paid |
| Devices | iPhone | iPhone, iPad, iPod — better |
| Requires iOS | 16.6 | 12.0 — better |
| Further details — not scored | ||
| Size | 4 MB | 10 MB |
| Age rating | 4+ | 4+ |
| Developer | Malcolm Mugglin | Jens Guell |
Customer experience
ChordMapMidi
JAX Stereo Tool (AU)
In-app purchases
ChordMapMidi
No in-app purchases
JAX Stereo Tool (AU)
No in-app purchases
Questions
Is ChordMapMidi free?
Is JAX Stereo Tool (AU) free?
Which has better reviews, ChordMapMidi or JAX Stereo Tool (AU)?
Do ChordMapMidi or JAX Stereo Tool (AU) have ads?
Which is updated more often, ChordMapMidi or JAX Stereo Tool (AU)?
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