Takete is an app that has been rumoured for a long time now, but has only just arrived on the app store today, but it isn’t cheap at $79.99 for the full app.
Here’s the app description:
Takete is an advanced audio visual performer featuring a unique set of tools for musicians and artists. Based on the phenomenon of synesthesia, Takete offers fine control between audio and visual elements to create immersive and tightly integrated AV works.
Combine audio and video loops with granular synthesis, drum machines, modular inline/send FX and extensive programmable and flexible behavior.
Recommended for iPad Air 1 or equivalent.