- Firebase Authentication - Firebase Firestore 

1. Firebase OTP Authentication 2. Saving user registration details in Firebase Cloud Firestore 3. Activating or De-activating a user from backend 

rules_version = '2'; service cloud.firestore { match /databases/{database}/documents { match /{document=**} { allow read, write: if false; } match /users/{document=**} { allow read: if isLogedInPhone(); allow create: if isLogedInPhone(); allow update, delete: if false; } function isLogedInPhone(){	return request.auth.token.phone_number != null; } } }