The sample app displays a list of GitHub public repositories for a given username. Tapping on one of them will open a repository details screen, where more information about the repo can be found. This screen also shows information about the owner of the repository. The /app directoy contains the implementation that follows the traditional standard Android approach. This is a couple of layout files, two Activities and the model. The model is exactly the same for the three implementations and it contains: Repository, User and a retrofit service (GithubService).