To get a notification on your tViewer app you have to set a simple logic, for when should be a notification sent.
In the example below, we have created a ‘Temperature Server Room’ check in the Checks tab. We set in this notification window, that the notification will be sent only to the user ‘James Bond’ to his tViewer app when the ‘Temperature Server Room’ check’s status changed from ‘any’ to ‘Warning’.