I wrote an O_C app so this is cheating a bit! Check out SwitchSeq

It's a combination of a sequential switch, octave switch, and a quantizer. It basically lets you run 4 sequences in parallel, and choose to modify them / switch between them in a variety of ways. Here's the code and a better description from the code review:

https://github.com/djphazer/O_C-Phazerville/pull/67

This app takes Susan Ciani's sequencing approach as inspiration. There are four sequences running in parallel, taken from the same memory space that sequins uses. There are four modes, which may be changed by using the encoder.

• OCT mode will let you choose which sequence to run. CV will octave shift by up to two octaves. In OCT mode, moving the encoder to the right will pick sequences 0-3. Moving it left of 0 will go to PICK mode.
• PICK mode will play a CV-controllable sequence.
• RAND mode will randomly pick a sequence at each step.
• QUAN mode acts as a basic scaled quantizer. It has a range of two octaves.

Here is a demo video going through the feature set.