It seems more or less like a popcorn time copy. It uses the node modules peerflix (https://github.com/mafintosh/peerflix), read-torrent (https://github.com/mafintosh/read-torrent) and socket-io (http://socket.io) for example. You can read the source code if you download the mac version and open Contents/Resources/app.nw inside the Isoplex package. But it is a good question why it is not on github.