After tracing the link below, my dummy Android application always got an unauthorized notification hub exception
https://azure.microsoft.com/en-us/documentation/articles/notification-hubs-android-get-started/
What could be the reason for this error?,
On
Did you verify that your hub name and connection string were filled in within the Android Application? You should have values for the lines:
private String HubName = "<Enter Your Hub Name>";
private String HubListenConnectionString = "<Your default listen connection string>";
Just a guess given the details provided
Make sure your phone's date and time are the same as Azure's. Or just use automatic time and date settings.