Due is a great little universal reminder and timer utility with lots of great polish. One of its many perks is that you can email a reminder to someone else, but it’s not just a basic email. Due creates a small icon your recipient can tap to add it to Due on their device.
To do this, simply swipe right across any reminder to reveal an action arrow. Among your options is “Email reminder,” and it does exactly what you think. Your recipient gets a styled email with the name of the reminder, a Due icon, and a link they can tap to add it to Due on iPhone or iPad. For bonus points, the email you send retains any custom reminder settings you have, such as to alert you every hour or minute and repeat options.
Due is a great utility that I use daily, despite being an OmniFocus junkie.