I found some tutorials about offline mode firebase for Ionic 2 but still I don't know how can I enable this thing in my application.
So, Is firebase realy support offline mode? If yes, can I store all recieved data and run the functions in offline mode?
There is no official support yet from firebase.But you can do that using angularfire2-offline library.
A simple wrapper for AngularFire2 to read and write to Firebase while
offline, even after a complete refresh.
Here is a great article about it: Offline Sync With AngularFire2
Ionic Offline Tutorial