I would like to have a simple free video editor that can cut and append files together without re-encoding. It's doable with avidemux, but it is just pain to manage.
I wrote one. It's actually a script driven by a video player that prints timestamps on standard out for specific keystrokes, along with a bunch of key combos for jumping back and forth, frame by frame if required. Ffmpeg is invoked at the end to cut the bits out and string them together, using 'copy' codecs.
Works well for the mp4 streams from my helmet camera, reliable key frames etc. For video that's been more highly compressed you'll need to compromise on the cut points if you want to avoid reencoding. And the cuts are abrupt, no fades or transitions.