1. SMS Retriever API

With this API, SMS content will be automatically read by our app. Here is the overview 

We need to set up both android and server-side for this.

Setup android-side

At first, when a user tries to log in our system, we want to pick up the user phone number from mobile and send it to the server so that server can send an OTP SMS to that mobile number. We can manually input phone number in the EditText or show a picker by Google Auth API to fetch the phone number from associated google account.