Vulse arrived back in June of this year. It claims to be the only app that lets you control effects whilst you play guitar by touching your screen and rotating your guitar. As far as I’m aware, it is. With Vulse you can mix and match combinations of effects like Wah, Pitch Shift, and Echo. Vulse also works with Audiobus & Inter-App Audio, so connecting it into your existing workflow shouldn’t be a problem. It doesn’t appear to be support audio unit v3 as yet, but who knows, maybe that’ll come along soon enough.
The app allows you to assign effects to the X and Y touch coordinates and the angle of your phone’s rotation. It uses multi-touch and hold-off mode enable new ways of interacting with your effects.
In the latest version of the app there are a bunch of new effects, including Phaser, BitCrush, and Resonator. These all appear to be in app purchases in the latest version of the app, but can be tried out before you buy them. In this version you can now add as many effects as you want to the chain, and configure the control methods for each, by tapping the control mode icon under each effect slot. There’s also a new distortion algorithm that now more accurately simulates and improves upon the tone and flexibility of real-life distortion effects.
As I’m not a guitarist this isn’t something I can properly test out, but it sounds like a good idea, and it does appear like an innovative way to mix a physical instrument.
Vulse is free on the app store, with IAPs (in app purchases)