Hi,
I am familiar with development for Android using Android Studio.
I have experience in making Android app to run 2 factor authentication using OTP sent to device using GCM. Then, the app wait for user confirmation (pressing OK), process OTP, and finally sent http request to server.
I am also familiar with deploying with git, revert changes, and using gitignore.
I am not sure about this project length. Probably you want hourly payment?
Feel free to contact me anytime.
Bram