Overview
River is a place to play freely, because you can always get back. Build a rig of AUv3 instruments and effects, save its states as snapshots, then play between them: launch clips on the bar, let modulation move the sound, and step back through any change you didn’t mean.
Sequencer
Clips
A clip launcher for every channel, with an arpeggiator and randomisation recipes like Glitch. Changes land on the bar.
Song sections
Group rows into sections — a verse, a chorus, a breakdown — and play through a section in order, each row repeating as many times as you set. Launch the next section when you’re ready and it lands on the bar.
Piano roll
Draw, brush and erase notes, paint velocity and probability, and hear every change on the next pass.
Modulation
LFOs, random sources, dials and MIDI controllers into any plugin parameter or mixer level.
Snapshots
Save every plugin in the rig, then crossfade the whole session from one to the next: instantly, over time, or by hand.
Undo
Three histories, kept apart, so stepping back through one never takes something from another.
Undo
The session’s structure: blocks, routing, sequences and tabs. ⌘Z and ⇧⌘Z, or the buttons in the tab bar.
Piano roll
Each sequence keeps its own history of note edits. Tap with two fingers to step back, without touching anything else in the session.
Per plugin
Knob and fader moves have a timeline of their own, so tweaking never buries a structural edit. A radial dial steps through every change in the session, and each plugin and modulation bank has a dial of its own. Saved with the session.
Technology
Built using AI
River is designed and directed by a musician and built with AI coding tools, held to the rules a real-time audio app needs: nothing that could stall the audio thread is allowed near it, and every change is checked for it.
Native SwiftUI
Written for iPad from the ground up in Swift and SwiftUI, with the audio engine in C++ beneath it. Every control is Apple’s own kind, so it feels at home on the glass, with a keyboard, and with a mouse or trackpad.
Privacy
No accounts and no tracking. Your sessions stay on your iPad.