As a user, I would like sound notifications to continually ring until an alert is seen.
Android phones have this option but iPhones do not. iPhone will only rings twice and stop. Having alert notifications continue to ring will allow users to hear the alert when sleeping.
Possibly add an option in user settings or Opsgenie mobile settings to turn on or off continuous notifications until the alert is seen. This would be different from the 'repeat' option in notification rules.
For now, users can use 'repeat' in the user notification rules, but this maxes out at 10 times with 1 minute being the shortest repeat time.