Purpose

Add-on allows you to set your own reminders to any JIRA issue you want. Reminder is the e-mail sent to user who created reminder in the issue.

How to

To create new reminder enter the issue and click on 'Reminder' button.

'Tonight' and 'Tomorrow' time are configured in Reminders Settings menu under your avatar (Morning time for tomorrow and Evening time for tonight):

Reminder for groups

If you have the "Create reminders for groups" permission, you can select the group name in the Who field

Periodical Reminders 

If you want to make reminders regular,

My Reminders

Menu under your avatar shows you all reminders created by you.