I use one called X-Plore. It’s actually very good. Even has a WiFi server, conpressed archive support, etc. but the downsides are that it’s close sourced and some features are behind a paywall (though IMO they are worth it).
So I was thinking of moving to some free or open source software. Any recommendations?
I guess the only good option is Simple File Manager https://f-droid.org/ru/packages/com.simplemobiletools.filemanager.pro/
I use CX File Explorer, it is free, but not FOSS.
I use a couple of simple apps, the gallery is great, the file manager is not amazing but it does the job, I guess I haven’t encountered many issues because I use it together with other apps (a different pdf viewer, a different zip manager, etc)
I used it too, the biggest issue is no webdav support, than zip support is bad, pdf viewer is bad, no built-in image viewer, so you always switching to gallery (it is great, but switching back and forth is not good) eventually I decided why using two file managers instead of one and CX is really good and simple to use.