Debugging an App on iPhone Device

This seemed like a really simple thing to do to me at the beginning. However I couldn't figure it out for myself and I've been looking online for a guide or something for hours to no avail.

I have an app that functions perfectly fine in the simulator however, when run on an iPhone device it crashes ... I am fairly sure it is due to memory issues. However these issues can't be recreated in the simulator. What I want to do is attach the xCode Debugger to the App while I'm running it on the phone. I have a certificate and profile and everything alre开发者_如何学Cady. I have no problems installing and running the app on the phone. However I can't seem to attach the debugger to it.

Any tips?