There’s a file-sharing app using I2P that’s been revived. It’s currently not under active development, but it is fully functional as-is.
As always, be careful with unknown programs. I take no responsibility for anything related to the program.
The file can be downloaded from within I2P, or here: https://ufile.io/y1uecxev
If you want to know more about I2P technology and anonymous overlay networks, go to https://geti2p.net/en/
Where is the source code?
https://github.com/zlatinb/muwire
Also included in the zip file I think. I took it all from the torrent.
Edit: Apparently not in the zip, just checked, but @kivullallo provided the link to the source.