The direct mode uses an ad-hoc network mode which to the phone looks as any other wifi network protected by a WEP key. Aside from a one-time setup to register the card, the transfer process is very seamless. At the time I setup my card I had to install the software on my PC. I'm not sure if you can now do all the setup from http://center.eye.fi/
What's even better is that now there is a wide selection of eye-fi connected cameras. I own a Canon PowerShot ELPH 300 HS, which by the way is a really great point-and-shoot camera. The 300 HS is one of the connected cameras. This means you get an extra menu for 'Eye-Fi Settings' when you're using the eye-fi card. This allows you to disable the wifi feature of the SD card when you don't need to use it.
You will need to recharge your camera's battery more frequently when using the Eye-Fi card. Every time the camera is powered (and there are pictures on the card) it will broadcast a wifi signal for 30 seconds (you can configure it to longer time using their software). The wifi broadcast goes off after a configurable period of time of no activity. When using a connected camera an icon will indicate if the wifi is on:
Another feature that you get with connected cameras is that it will display an icon once a picture has been transferred:
To connect your to your Eye-Fi card using the iPhone application simply power up your camera and connect as you would to any other wifi network. A wifi network that begins with 'Eye-Fi Card' will show up in your available networks. It is protected by a password and unfortunately the only way I know of retrieving the key is using the Eye-Fi center software.
Launch the Eye-Fi Application and you will see the pictures being transferred right away. This application can run in the background so as long as the camera is on and connected via wifi, it will continue transferring in the background. The application has improved a lot since the original version, it now provides more feedback as to what it is doing and the transfer is more reliable.
There are more and more wifi enabled cameras in the market and they are becoming more affordable, but they don't provide the breadth of features available through smartphone applications. Cellphone cameras are also slowly becoming better, however they still lack in zoom, focus, motion and low light performance. If you already have a good point-and-shoot or DSLR camera, this is a convenient and affordable way to transfer your photos into your smartphone when you're on the go. The Eye-Fi Connect X2 4GB retails for only $29.99.