Latest Snapshot
The snapshot is something like a release, but because of the lack of a fixed plan when which feature has to be implemented and when is it finished enough to call it final, I don't like to call it this way.
You find it here on SourceForge.
Bleeding Edge
If you always want the newest stuff, with the risk that something is currently broken, then download direct from GitHub the tarball.
Or preferred, clone your own copy of the repository. To do so you have to install git previous.
git clone https://github.com/loh-tar/filu.git
The advantage is that you have not to download and compile the whole source code when you want to update your installation, but only the things which was changed.
Furthermore could you now easily start your contribution :-)