this app uses: android architecture component's ViewModel and LiveData. Firebase for Database and Authentication. This app is in development phase. You can tryout the app here:
https://drive.google.com/open?id=1Sq0iwcLCtZxgMlxOBy9jnDfC5X94oZCc
if you do try then give the feedback at ashtube30@gmail.com with subject "ComplaintBox Feedback"