It could be a great improvement to add condition on specific event.
Example #1: If Resolved Notification is sent, don't send Updated Notification (because a Resolved Event include that the Issue is updated).
Example #2: Don't send a Commented or Updated Notification, if the issues Resolved.
Another great improvement should be to be able to customize the e-mail (Subject & Description) that is sent as a Notification.
Example #1: Add the status in the subject of the e-mail: [JIRA] Resolved: (TEST-679) Summary, Statuts, etc.
Example #2: Be able to customize the e-mail or add custom field by linking a notification to a Screen.