APG Composer is both a fun tool to play around with and a proof of concept that shows that the Audio Plugin Generator can also produce iOS apps*.
dlab says "Basically, there was no app-specific code written for this app. We could therefore take any Simulink model, compile it to C code using Simulink Coder, add that code to the current project (containing the APG source code) and voilà, we have a new app that does something completely different (e.g. a signal generator, a vuvuzela filter, whatever, ...), and it will come with its own auto-generated GUI."
If there is a demand for such an iOS app creating feature, dlab may add it directly to the Audio Plugin Generator in the future.
As a side note, the sequencing part of the APG Composer app was modeled after a hardware sequencer which is shown here.
* NOTE: the current APG product does not yet support the generation of iOS apps.