They told somewhere in their website (or was it in Github) that the project is deprecated. They even don't seem to respond to pull requests, which is bit alarming. The reason for it might have been their new commercial websocket service.
I myself used NowJS in my first websocket applications, but have then moved onto Socket.IO and other more niche kind of solutions. NowJS lacked and still lacks some newer features and it is bit buggy. If I would be you, I'd just try my best to adopt something which is and will be maintained for some time, or just start from something simple and build my own.
To answer to the original question, yes.