From time to time I got the need to trim intros/outros or silence from downloaded audio files.
I’m currently using Super Sound, but I find it a little silly that one of the last closed source, filled with ads app I still have installed is for such a small functionality.
On desktop I use ffmpeg for pretty much anything, so if there is some wrapper for it over android it would be ideal.
WavePad is open source but it’s free for non-commercial use and it’s pretty nice. Handles a lot of formats out of the box.
*Edit: Oh, that would be for desktop. Just noticed I was in the Android /c