Piggybacking to mention that the download links on their landing page are all hosted on SourceForge, but their releases page on GH has the same version (1.5) for all three platforms:

https://github.com/dalboris/vpaint/releases

I won't download any binaries from SF if I can help it, due to the recent unpleasantness.

and the paper is at http://www.dalboris.com/research/vac/vac.pdf