One Click Signup with Mobile Number
Facebook and Gmail provide one click Signup with Email id , but for Mobile only few SDK’s are available.
One of them is TrueSDK https://developer.truecaller.com/ very lightWeight 100 kb in size and easy to integrate in 5–6 steps only and you can get one click Sign-in the app.
Apart from easy integration it will handle the Mobile Churn cases and help you to figure out not activated mobile number’s easily . Also the app can save a lot of cost in the OTP/SMS flow.