It's been more than three years now, that I have started to implement my first chat application. Don't ask why I don't know the answer either. But it's a fact, implementing chat applications became a part of my life.
There were lots of different variations. First I started with a Parse only chat, then I continued with a Parse + Firebase combination, and when Parse was shut down I switched to a Firebase only solution. Since Firebase local data store was not reliable enough, so I started to use Realm for local caching.
Later on, I added Audio and Video calling features, this way the app started to look more like an all-in-one messenger rather than a simple chat application.
Here we are now. But there are lots of things to do. I am currently working on version 3.0. More and more features are coming up. Stay tuned. :)