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?
Total Commander
X-plore, even paid for it.
It has replaced ES File Explorer 3.2.4.1 that I’ve used since 2014.
Not FOSS, but I use Files by Google, FX File Explorer and old version of ES File Explorer.