LoginForm1 is about username and password validation. It is very simple. It checks whether username and password, if they are gamze and sen then it is redirected to success activity. If not, then redirected to login activity.
SessionDeneme01 is about creating and deleting session info with usage of Shared Preferences. With SharedPreferences, if user closes the application, session info remains.
FirebaseDemo02 is about using firebase for android application database operations. I have 2 tables in database. I add records to them, show records in user table in listview.