Flash-Dock (http://www.pocketdemo.fr/flash-dock/) is a new, US$39.99 solution that “brings the touch screen of a smartphone right next to DSLR setting screen and buttons.” Basically, it’s a for devices such as the iPhone that’s positioned in the flash-socket of DSLR cameras — also called the “hotshoe” adapter.
Among other benefits, Bruno Rousseau, founder of pocketDEMO says the Flash-Dock makes it simpler to use EyeFi SD cards — SD Cards that store pictures and send them to a smartphone through a built-in Wi-Fi chip. He says it also simplifies geotagging with .GPX files, geotagging with Bluetooth, calculating depth of field and lightmeter calibration.