I have the new iPad and the lightening to USB connector issued with the iPad works perfectly with IMP99D as long as you use the 2 amp side. As for the iPhone 5, I would assume it would work but I'm not sure if you would need the 1 amp or 2 amp side to power it. I'm on vacation with the NewTrent and I love it. Hope that helps.
I know it works on the new iPhone 5 if you use the 2.1 amp port that was designed as the "iPad" port. This would lead me to assume it works for the 4th generation iPad as it works works with my new iPhone and the 3rd generation iPad.