Chapters: Overcast now supports chapters in MP3, M4A and M4B files , allowing you to skip back and forth to particular sections of the file, assuming the creator of the file put them there to begin with.
Right now the ATP podcast is the only one I listen to that puts chapter marks in their podcast episodes. I find it very handy since, if they happen to talk about a bunch of topics that don’t interest me, I can skip them pretty easily.