SharePoint Alerts Add-in for Office 365 sends alerts, reminders and notifications from SharePoint Online via email and builds a flexible notification system on your SharePoint site. Alerts Add-in has a wide range of settings for scheduling, setting event criteria and email template building with field values. It expands basic SharePoint Online features of notification system and provides a convenience user interface and high productivity.
SharePoint Alerts can be sent to a specific user or a group of SharePoint users within a specified timetable (i.e., hourly, daily, weekly, only within business hours — from 8 AM to 5 PM. or at any other specific schedule). All alerts can then be combined into a single ticket, instead of being sent in several email messages.
With SharePoint Alerts Add-in, you can create complex terms and conditions for sending SharePoint Alerts. An example would be for you to receive SharePoint notifications when a column value or status changes, your task is overdue or a document is updated.
You are able to create the reminder message within seconds. The SharePoint Alerts Add-in enables users to use different text styles in the HTML-based template body, add pictures, tabs and links. And customizable Email templates would allow you to create alerts using just a couple clicks.
SharePoint Alerts Add-in allows users to always be on schedule, effectively work on their tasks and ensure any important events are not missed anymore.
You can send alerts immediately, daily, weekly or based on the field value of the date in your list, send alerts X days before or after certain date of the date field value.
Online documentation: http://www.virtosoftware.com/manual/alerts-app-for-sharepoint-online
You can use up to 10 alerts for your tenant for free. If you need more alerts visit http://www.virtosoftware.com/office-365/alerts-app-for-sharepoint-online for more details.