Microsoft acquires hockey app back in 2014. And now decided to shut down its services. Microsoft official announcement on Nov-16-2018 is to shutdown hockey app after a year on Nov-16-2019. If you are using hockey app than you will get an email by Microsoft for this announcement. And you are advised to shift to app center any day before Nov-16-2019 because it is no longer supported by Microsoft after this date.
In 2017 Microsoft already announce visual studio app center as the future of hockey app. but now official deadline to retire hockey app is revealed.
Hockey App is used for testing, distribution, get crash reports and analysis for beta apps. There are several engines operating for testing and distribution by other companies. Like testflight and google playstore beta feature is used to test native iOS and android beta apps. But hockey app did it all and give crossplatform support. Which is now officially handover to app center. It doesn’t mean that you will get all the features in app center but Microsoft has its defined roadmap for app center.