How to repeat SMS message alerts indefinitely until read? I would like to enable repeated audible alerts of new SMS messages on an iPhone 6.  Specifically, I want the alert to be repeated indefinitely until I read the message.

This is because it is inconvenient for me to carry my phone with me around the house, but it is important for me to hear an alert when I return -- perhaps an hour or later -- to the room in which my phone is stored.
I think that the closest you can get is to change the number of "Repeat Alerts" for the Messages app in Notifications, but keep in mind that the maximum number of repeated alerts is 10 (at two minute intervals).

To change, go to Settings > Notifcations > Messages > Repeat Alerts.

Not a solution if your gone for an hour, but will get you up to 20 minutes.