Here’s a jailbreak tweak guaranteed to put a smile on your face if you’re a music junkie. It’s called Plugication and it automatically resumes your music when you plug your headphones into your iOS device, negating the need to open up the Music app and resume it manually. Best of all, it’s completely free.
Plugication Tweak Automatically Resumes Your Music When You Plug In Your Headphones [Jailbreak]