Greasy Fork is available in English.
Adds a download button to the video player.
Nope. I'm keeping user script development separate of my other projects. Since it's just a few lines of code anyway, I didn't think of collaboration so far, but I'm very glad to incorporate and credit your contribution. :) Just send me a Git patch file via email.
Collaboration?
Do you have this on github or any other platforms where someone could suggest changes?
I'm currently patching in support for vimeo's embed player and would like to contribute back once it's ready.