Socket.io can be implemented using different languages. Very easy to use with Node.js and also this is open source. If your app uses push notifications this is perfect fit for you. Socket.io has provided one of the best documentations.

I really like how light socket.io is, all the files size weight small amount, with just a few commands you would be able to create a real time application and it works with nodejs which is a really good programming lang, my customers loves socket.io because all the statistics are updating without any delay, socket.io is the best !

I really like the simplity on socket.io, you are able to create a fully working real time website or features on the website, with a few lines of code, my customers find socket.io really reliable, 99.99% up time, it's working with nodejs which is awsome because i find nodejs really fun to use and to learn, and its very easy to install and setup.