IMPSY vs Fishtail
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
IMPSY
Read full descriptionHide full description
Jam with an AI MIDI partner on iPad and iPhone. IMPSY listens to what you play and improvises musical responses. Load it as an AUv3 MIDI Processor in AUM, AudioBus, Cubasis or Logic Pro for iPad, play it from a USB or Bluetooth controller (or the on-screen faders), and route its output to any instrument app. IMPSY also runs on its own: it appears as Core MIDI virtual ports (IMPSY In / IMPSY Out) and connects directly to a plugged-in controller, so you can play it without a DAW. How it works IMPSY runs a Mixture Density Recurrent Neural Network (MDRNN) on-device. Every note, control change or pitch-bend you send becomes input to the model, which predicts what comes next, including the timing of the response. Shape the conversation with: • Threshold: how long IMPSY waits between your input and its reply • Sigma Temperature: randomness of pitch and control values • Pi Temperature: randomness of which musical "idea" the model picks • Timescale: speeds up or slows down the response • MIDI Thru: passes your own playing through to the output alongside IMPSY's Connect anything • Map each model dimension to any MIDI message (notes, CCs or pitch-bend) on any channel, independently for input and output • Connect a controller directly, or use the always-on IMPSY In / IMPSY Out virtual ports • Import and export your mappings as TOML, compatible with the IMPSY Python toolkit Custom models IMPSY ships with a default 9-dimensional model trained for general musical interaction, but you can load any .tflite model trained with the open-source IMPSY research toolkit: synths, drum machines, lighting rigs, or anything that speaks MIDI. Accessibility IMPSY is built to work with VoiceOver and Dynamic Type. Every control is labelled, the sliders are adjustable by VoiceOver, and status shows as text, not colour alone. Full statement: charlesmartin.au/impsy-auv3/accessibility.html Compatibility • AUv3 MIDI Processor, no audio I/O • Hosts in AUM, AudioBus, Cubasis and Logic Pro for iPad, or any other AUv3 host that supports midi processors. • Also runs standalone with Core MIDI virtual ports and direct device connection • Requires iOS 17 • MIDI stays on-device. No network, no telemetry
Fishtail
This app generates complete musical forms using algorithmic composition based on music theory. Users can shape, perform, and rearrange these compositions, routing seven musical channels to their chosen instruments via MIDI. It offers extensive control over keys, modes, and expressive elements.
- Algorithmic music generation
- Multi-section compositions
- Seven-channel MIDI output
- Retain, reorder, and perform Takes
- Multiple intonation systems
- AUv3 MIDI plug-in support
- Ableton Link integration
Read full descriptionHide full description
Fishtail is a generative MIDI instrument for iPhone and iPad. It composes complete musical forms, then lets you shape, perform, retain and rearrange them! Fishtail does not use AI to generate music. Its musical output is created through algorhythmic generation grounded in musical theory. Build pieces from sections with independent keys, modes, meters, cadences and expressive treatments. Generate distinct Takes, compare them, reorder them and hand the next Take over at a natural whole-piece boundary. Fishtail produces MIDI rather than sound. Use it standalone or as an AUv3 MIDI plug-in, and route its seven musical channels to the instruments you choose. Ableton Link supports shared tempo and transport. Features: • Complete multi-section generative compositions • Seven-channel MIDI output • Retain, reorder and perform Takes • Seven intonation systems • Normal MIDI, pitch-bend and MPE output • MTS output • Ableton Link • .fishtail project save and recall • Standard MIDI and per-channel export • Experimental analogue CV file packages • Accessible light and dark interfaces No account, advertising, analytics or tracking. Tested in AUM
Screenshots
Verdict
The clearest difference is price: IMPSY at Free against Fishtail's $14.99. On ads, in-app purchases, device support and iOS requirement 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
IMPSY is free to download; Fishtail costs $14.99 up front. Neither carries in-app purchases, so what you see is what you pay.
| Parameter | IMPSY | Fishtail |
|---|---|---|
| Price | Free — better | $14.99 |
| Rating | — | 5.0 (3 ratings) — better |
| Positive reviews | — | 100.0% of reviews |
| Number of ratings | — | 3 — better |
| Update frequency | — | Every 2 days |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | — | Paid |
| Devices | iPhone, iPad, Mac — better | iPhone, iPad |
| Requires iOS | 17.0 | 17.0 |
| Further details — not scored | ||
| Size | 18 MB | 26 MB |
| Age rating | 4+ | 4+ |
| Developer | Charles Martin | AMY NICOLA MCBRIDE |
In-app purchases
IMPSY
No in-app purchases
Fishtail
No in-app purchases





