Online User Authentication Mobile App in JAVA and Android.

Online User Authentication Mobile App., is a user authentication android-based app that verifies user by sending One Time Password (OTP) to a user’s mobile number by using Firebase authentication. One time password (OTP) code is used to sign in your application by sending an SMS to user’s device by using Firebase Authentication. When a user receives OTP code, it enters in your app., for login. If code is matched correctly, it successfully login and access the app., otherwise it generates the message” invalidate code”. Functional Requirements: 1. Create the user registration profile: user need to first register himself into this system by filing up the basic registration details. Like user name, email id, mobile number. 2. After completion of registration, OTP code will be sent on his/her registered mobile number via SMS. 3. After that user enter the OTP code in login page, if the user passes the authentication, then system will redirect to the main page. 4. The OTP code is randomly generated by the system at the time of login. 5. To create an app and add user interface elements such as Buttons, edit texts, and Text views use android IDE. 6. Add your project to Firebase console and enable phone authentication. 7. Implement click listeners on buttons to sign in (Generate OTP) and sign out. 8. Call Firebase authentication methods on the button on click events. 9. Retrieve user mobile number from firebase user data.