So this is the best alternative I have found. Settings>Notifications> then scroll all the way to the bottom and under "Looking for something else?" tap Notification reminder. Turn it on and set the remind time (shortest interval is every 3 minutes) and then select they apps you want it to pertain too. I chose Selected Apps because I wanted to be reminded about emails and a few others. Unfortunately when you enable this, every single app is turned on by default so you have to go down the list and turn off the ones you don't want. It only took me a few minutes but if you have a ton of apps it might take a little longer. I will test it out when I get a chance but this should do the trick.
Update: Just tested it and it does work, I get a notificaiton sound every 3 minutes.