JPSoundEnginePlug in.
Play.
Plug in a USB or Bluetooth MIDI keyboard and your iPhone or iPad becomes a SoundFont sound module.
From pianos to drums, ready out of the box.
GeneralUser GS, a GM/GS-compatible sound set, comes built in. You can also import your own .sf2 files from the Files app. Star the instruments you use most and recall them with one tap.
Shape the sound with knobs as you play.
Volume, expression, reverb, chorus, release, pan and bend range. When you play from an external keyboard, hide the on-screen keys to show large knobs. Drag up, down, left or right to turn them.
Hold a chord. Hear an arpeggio.
Turn on ARP and hold a chord, and it plays the notes one by one in time with the tempo. Choose the play order, note value, gate, swing and a 16-step pattern, with 10 classic pattern presets. The settings open over the top of the screen, so you can change them while you play.
16 channels,
each with its own sound.
Set the receive channel to Multi, and notes from your DAW or sequencer play a different instrument on each channel. The built-in demo songs let you mute or solo parts, or pick a part and play along.
Features
- Keyboards
- USB MIDI, Bluetooth MIDI (BLE)
- Receive channel
- All (omni), any single channel 1–16, or multi
- Sounds
- SoundFont 2 (.sf2). GeneralUser GS v1.44 built in
- Playing
- Velocity curves, transpose, octave shift, hold, pitch bend and modulation wheels
- Arpeggiator
- 6 play orders, note values from 1/4 to 1/32 (including triplets), tempo ♩=40–240 with tap tempo, octaves, gate, swing, latch, and a 16-step pattern with 10 classic presets
- Audio
- Keeps playing in the background, and can mix with audio from other apps
- Devices
- iPhone and iPad (iOS 26 or later). The number of keys and the layout adapt to the width of the screen
- Languages
- English, Japanese
Coming soon to the App Store.
Once it is released, you can download it from this page.
Support
For bug reports and questions, please contact @junpeiwada on X. Including your device model, iOS version and MIDI keyboard model helps a lot.
Privacy Policy
Effective: October 23, 2026
Information we collect
JPSoundEngine does not collect any personal data. There are no accounts, ads, analytics, or crash reporting, and the app does not connect to the internet.
What stays on your device
- Your settings (receive channel, transpose, velocity curve, volume and so on) and your favorite instruments
- SoundFont files you import (stored in the app's Documents folder, visible in the Files app)
None of this leaves your device, and it is removed when you delete the app. It may be included in your device backups.
Bluetooth
Bluetooth is used only to connect Bluetooth MIDI keyboards. No information about nearby devices is stored or sent.
Changes to this policy
If this policy changes, this page will be updated along with its effective date.