Android : Chat Feature in Android

I want to develop a chat feature for my android app. I have looked all over for options. But it's got more confusing with so many different options for server and client side functionality that it's difficult to consider which seems the best.

These are the options I have in consideration right now:

1. Use a service such as QuickBlox which provides very good add-on features for chat.


2. Use Service such as PubNub or Pusher or Firebase, which are different options all together.


3. Use Google's Mobile Backend Starter, which in my opinion does not seem scalable/cost effective for 1:1 chat sessions. Considering it's in sort of preview mode.


4. Use Google Cloud for XMPP server side code in Java or Python and it's Entities for data storage. But the reviews from some developers question the deliverablity of GCM


5. Use a jabber client and jabber server. But I have got no clue how to deploy the server.


6. Use socket.io as opposed to jabber for services.

Considering the best use-case of easy development + feature requiring saving of chat history + future changes to the code. What seems to be the best option for chat feature implementation ?

Thanks in advance for help as this has got me baffled since a long time.