Edit sound on iOS

I did my first iPad only video today (actually pretty much my first video) and discovered one thing more or less at once … editing sound files wasn’t obvious to me, it seems to be a bit limited in iMovie (or I haven’t understood how to do it). I had recorded the sound on a Zoom H1n and imported that into iMovie, but then it seemed really cumbersome to find the interesting clips from that rather longish file.

So the question is, do I miss something obvious (I couldn’t see the whole clip and the only way I could find was to cut away snippets from the beginning until I reach the interesting parts … there has to be a better way!!) or should I use some app first to create the sound snippets I want? (if so, any recommendations?)