iOS Unpaused Application from Bluetooth

I am writing an app that is not a game. It communicates with an External Accessory via Bluetooth. I have everything working where I can get notifications in the background when a Bluetooth device connects or disconnects. I also get the data messages while in the background.

If I get certain types of messages I need to be able to bring the app into the foreground. I am pretty sure this is not something I can do automatically and may need user interaction and that is ok. I just need to know how to do that. Is there a way to show a notification to the user or something?