Code is here https://github.com/AndreiD/UltimateAn...
remember to star the repository please
Retrofit is one of the most popular HTTP Client Library for Android as a result of its simplicity and its great performance compare to the others.
Retrofit is a REST Client for Android and Java by Square making it relatively easy to retrieve and upload JSON (or other structured data) to a REST based webservice. Retrofit can be configured with converter is used for its data serialization. Typically for JSON you use GSon but you can add custom converters to process XML or other protocols. Retrofit uses the OkHttp library for HTTP requests.
here are the gradle config files:
compile 'com.squareup.retrofit2:retrofit:2.0.0-beta3'
compile 'com.squareup.retrofit2:converter-gson:2.0.0-beta3'