Turn your iPhone or iPad into a musical instrument with RD4 - Groovebox, a music-making app featuring virtual analog synthesizers, drum machines, and effects. Compose and arrange music in real-time by selecting instruments for the 4 channels. Record live performances or use the sequencer and piano roll to set notes for each instrument. This app is designed for both experienced musicians and beginners, offering a multi-touch interface for creating unique loops and musical phrases.

Upgrade to the premium version via in-app purchase to unlock features like saving songs, exporting loops, audio session recording, sharing sounds, accessing all drum kits and effects, mixer and effect bus configuration, MIDI input, and MIDI clock sync in/out. Manipulate synthesizer sounds by tweaking oscillators, filters, and envelopes, and add effects like reverb, distortion, phaser, filter, and delay to enhance your music.