Excerpt: I have a card in two different cameras and was shooting an event. Both cameras were sending photos to my phone at the same time. This was exactly what I was looking for and was simple to setup.
Pros: Excellent Interface, Fast Transfer, Lightweight
Excerpt: We put this in our Nikon D7000, and paired it to my wife's iPhone 5. Easy enough to setup, and works great! Only three caveats: 1) Somehow we don't have the "share to Facebook" button in EyeFi Mobi that we should. So we have to transfer the photos from Mobi to the phone gallery, and share from there. 2) If we transfer photos throughout a day of shooting, we end out transferring the same photos multiple times.