Chatapp Based on Firebase database by Google The code is mostly written by me and with the help of Stackoverflow You can copy the code, there is no copyright on it.
If anyone try to rebuilt such chatapp please use Firestore, it is more feasible to use. I have used Realtime database because Firestore was not released when i was working on this project.
This app will not work untill you put your "google-services.json" file in the source code.