Hello there!
I am Andy, I am bootstrapping this product called PieSocket.com and have grown it to $800 MRR in the last 8 months.
I started this to build a video room to watch movies with my girlfriend (who then lived in a different city) in sync. i.e. to build a remote-controlled video player.
We provide the services at Lower costs than Pusher and Ably, and recently launched the unique "Realtime on blockchain" feature.
If you have used Pusher or Ably, I will request you to give PieSocket a look and help us improve.
DM me on Twitter for discounts: https://twitter.com/sudoanand