sms notification app

hi i don't know of a reminder app, but you can get an sms reports app which will tell you when a message has been recieved, but it means that you have to go through the app every time.lori

There are no third-party apps that can change the core phone features. The features you want would have to come from Apple.

You can suggest them here: http://www.apple.com/feedback/iphone.html

provide additional notification when an sms arrives or maybe has gone for a while unread? like a reminder?

Settings > Messages > Repeat Alert
This will give another alert after five minutes, and one more after ten minutes.

The app exists. I installed it. It just adds *!# before the text of the message to be sent and it works with Vodafone Italy. In works in a transparent way over the SMS original program on iPhone4.
With the app installed you can also use the original program and do not get the notification or you can add manually the code *!# and be notified...
It was the only way to get the notification.
I have a BIS Service with Voda IT (2 Sims with same number and you switch Slave and Master with 1011#) - The stupid thing is: if I set the delivery notification ON on the second Phone (not iPhone) it works but if i switch the iPhone to be Master it does not work. That means it is not only a matter of setting the net. It looks like something left by Apple in the hands of Phone Companies to work wit iPhone.
YOU FIND IT HERE
http://itunes.apple.com/it/app/rapporti-di-consegna-sms/id380745756?mt=8