I want to make an app where while the user is pushing down a button the phone vibrates until the user releases the button.
Ive searched around and I haven't found a way to make it a long vibrate, except for a very old tutorial from 2009 which seems to be outdated.
It's not allowed by Apple to use the vibration as you want to:
It's not the method, but the result, that's not permitted.
Source: http://10base-t.com/unofficial-appstore-rejection-criteria/
Look on these options,
also
Making the iPhone vibrate
And, you need to import AudioToolBox framework,
repeat this line in between you start-stop vibrate. don't forgot to add and import
framework to your project.