For one, Eyefi Cloud requires a camera that takes SD cards. This eliminated my older Canon SLR, which uses CompactFlash. However, of all brands come equipped with Eye-Fi support: Simply insert the card and find the configuration options in the settings. When I inserted the Eyefi Mobi card into PCWorld’s Canon EOS Rebel T3i, that’s exactly what happened.
Oh, and the EyeFi cards don't necessarily play nice with all USB card readers. EyeFi claims that they're completely compliant with the SD spec; they use some features in the spec that aren't commonly used by normal SD cards, and many readers don't support those features and thus don't work at all with the card. They bundle a reader with each card, but it just seems like an additional embuggerance. My netbook's builtin reader works quite happily with our card, but the same can't be said for the Sandisk reader I have on my desktop machine.
Images and videos can then be automatically transferred to your phone or tablet via a secure Wi-Fi network built into the card. We found this worked just as it had with the earlier Mobi cards. On our iPad 2 this meant needing to manually connect to the Eyefi card's network before files were transferred, while on an Android Moto G (2nd Gen) this was done automatically. Within the Eyefi Mobi app you can then view photo attributes (EXIF), perform basic edits (orientation and crops) and share images. You can also organize and sync them across devices via the , and each Mobi Pro card comes with 12 months access, normally US$50.