Free hosting is not supported
Most free hosting providers attach analytics to your site content. This makes the app unable to load the data from the server. Most free-hosting providers remove the analytics when you upgrade to their paid hosting.
Make sure Server Url is correct
Make sure that the server url in the Android app, Configurations.java file is correct. Also, make sure that your SERVER_URL contains a '/' at the end. This is required for the app to work properly.