No, this is more legal since this doesn't use torrents so you aren't uploading and it might be completely legal in Canada, I'm not sure. Also this has absolutely nothing to do with Popcorn Time, Popcorn Time uses other people's architecture while MovBucket has it's own server and a list of movies that I maintain.
Well, not on my own server but yeah. I'm planning on making a Linux and Mac versions since this is basically Node-Webkit and an embedded website, and can be easily done, but I'm experimenting currently. I will make something like that soon. Also Android App is in the works too.
Edit: Also if you want you can download Node-Webkit and the source code of my app and probably build a release. I don't have a mac to test.