It's just neural-style implementation according to about page. https://github.com/jcjohnson/neural-style
You can install it and run it yourself. You need linux distro and 4+ GB of ram and good processor, or nvidia gpu with at least 2+ GB vram, and of course, a bit of free time for processing. These aren't official requirements but what I think since I run it once in a while. For example this low-res pic took me 4 minutes on gpu but since it broke I have to use cpu now, pic of similar size now takes me 18 minutes. But this is low res pic, processing 512x512 pic fills up my 8 GB of ram easily and takes an hour and half to process.