S-modular is a new app for your iPad based around a modular synth interface. Similar to Reaktor’s Blocks, S-Modular is semi-modular, meaning you’re restricted to particular modules but can patch them together in different ways for varying sonic results. The iPad’s touch-screen lends itself well to patching and S-Modular also offers support for Audiobus to allow other apps to interact with the semi-modular music-maker.
It’s available now for a fair fee of $3.99 – worth a punt if you modular is intriguing you. If that’s still too much, you can download a free Max for Live device that mimics Mutable Instruments’ modules or this free open-source modular synth. Tasty.