Things like this always seem to come out a few months after the latest iDevice and then are only compatible only with older ones for one reason or another it happened before the Lightning connector with other add ons
It's compatible using the 30-pin to Lightning-adapter. Not sure how convenient this is, though on the other hand: using the 30-pin *cable* to Lightning adapter would move it away from the iPhone a bit, which could(?) be an advantage.
As others have pointed out, though: Things like the Sony PCM-M10 now cost $250, are about just as portable, have incredible battery life, and very good internal mics.
I couldn't be more happy with the thing (and, of course, it's very nice with the NT4), so not sure I would spend $200 on the iXY.