The following is the high level overview of how the SDK works to simplify the process of validating a phone number within an application running on Android.
Along this guide we're going to implement a sample app from scratch, integrated with the Twilio Verification SDK and supported by a sample token server.
There’s also a more complete sample app already implemented.
Once the SDK is integrated in your app and your backend is capable of generating the JWT, you’re good to go.
You can also make use of the Google’s sign-in hint, which auto-fills connected phone numbers for the user and reduce the friction even further. Check out the official documentation or ask our support team for more information on how to use Google’s sign-in hint. Smartlock passwords - Hint Request API
The Twilio Verification Sample App has implemented this feature and is available in github
It will also be implemented in the latest release of the Authy app, starting roll out on May 2017