Sounds a bit like Sciral Consistency. Sadly, it seems to be more or less abandoned (just look at those old screenshots!). I thought it had a great interface for handling flexible repeats. http://sciral.com/consistency/
You might also look at the myriad “Habit tracker” type apps. I’ve seen at least a handful that let you define custom repeat schedules, skip days, etc. I won’t recommend specifics since I’m in the macOS/iOS ecosystem.