A while back I posted my guide to running your own audio (seen Here). With the new types of interfaces the idevices adopted (the "lightning" charger) you might be wondering if my advice still applies. It does but be aware of this - Much like in magic, do no buy cheap knockoffs.
They make a lightning to 30 pin adapter but due to cheap unauthorized versions coming out of (just guess where. I bet you can get it in one) you need to be aware that a genuine apple made adapter, at this point, is the only one the ijet will work with.
Always ask for the real deal.