Are there any chat application plugins available for Web, IOS and android?

I am building an application similar to carpooling and I want to implement the chat feature in that, whenever user wants to contact driver he can chat over web and if the driver has mobile application the message should be delivered to mobile and if driver replies back from mobile the message should reach user immediately in web or android or IOS.

Here the challenge is user can chat from any device say web or IOS or android and in the same way driver can use any device say web or ios or android. I am stuck with this since very long can someone help