Authentication Flow With React-Native and Firebase

I am new to React-Native Framework for App development. I just finished with the basic authentication process for

users of the app using firbase as my backend and utilizing AsyncStorage for SignUp and SignIn Persistence. Although it worked as i wanted, but i need to know if performance is optimized with how i did it. So i am searching for a someone to please review help review my work. https://github.com/Yingi/AlphaRides