In this application we can simply chat with other user in real time. you don't need any server setup, it is completely base on firebase. this app project cover firebase login, real-time DB, file storage.
Just create your firebase account setup real-time DB, login and storage. checkout these video first:-
Getting Started with the Firebase Realtime Database on iOS - Firecasts https://www.youtube.com/watch?v=joVi3thZOqc
Getting Started with Firebase Storage on iOS - Firecasts https://www.youtube.com/watch?v=Bd4-6pnjjd8
https://www.youtube.com/watch?v=PrXmRaoZmD4 Getting Started with Firebase Auth on iOS - Firecasts