Just heard about this on Reddit and didn't see a thread here. I've been considering getting a DAC and an amp to use with my iPhone 5 and this looks perfect for the price ($249)
I emailed Jason from JDS and he says it DOES work with iPhone 5 (and other devices obviously), you do need a Lightning CCK to make it work but the C5D comes with the USB/USB mini cable you will need.
He also said that it works with every iOS app they've tried, I asked specifically about AmpliFLAC but he said he hasn't tried it yet but will download it and report back.
They will be publishing a "release article" in a few hours.
Here's a link to the C5D product page on their newly re-designed website
Edit to add:
Edited by MattyB37 - 11/8/13 at 9:01am