Android app to authanticate using auth2 by ekm2evans

I need a very simple example app that is able to authenticate a user through quizlet.com and make api calls.  Here is the site describing what I need done.  https://quizlet.com/api/2.0/docs/authorization_code_flow/ I need the app to be very simple… (Budget: $30-$50 USD, Jobs: Android, Mobile Phone)