* free acc can only has 2 app, once add new app, it has one month trial. price: https://www.hockeyapp.net/pricing/ ($30/mon at least)
https://azure.mocrosoft.com/en-us/pricing/details/hockeyapp
* ios depends on apple's provision profile, hockey app only help to collect tester's udid by sending invitaiton.
* https://support.hockeyapp.net/kb/client-integration-ios-mac-os-x-tvos/known-issues-with-ios (ios issues)
* distribute app: https://support.hockeyapp.net/kb/client-integration-ios-mac-os-x-tvos/how-to-install-ios-beta-apps (send by mail, or web clip)