In order to use the app you will need to provide your own api key.
If you dont have a key than go to this link to sign up:
https://www.themoviedb.org/account/signup
then click api and get an api key
When you have an api key
Go to MoviesActivity.java and on the 24th line replace public static String apiKey = ApiKey.apiKey;
with public static String apiKey = "REPLACE_WITH_YOUR_API_KEY";