Hourly Reminder

On your iPhone, you can use the Reminders app to set a reminder every 2 hours. When you create a new reminder, in the Details section (you can touch the "i" icon for an existing reminder), you can set the Repeat functionality to "Custom" and set it to 2 hours.

I just updated my iPhone and the hourly reminder went away?!!!?!?

You need to make sure that your reminders are being synced to your iCloud account. Settings>Reminders>Accounts. That feature will not work on any reminders not synced to iCloud.

I tried and it shows daily weekly but no hourly