Pocket Light Meter reads the lighting conditions in a location, and displays the appropriate settings to help you get the perfect shot. You can buy a light meter to carry along with your camera, or you can download Pocket Light Meter to your iPhone, iPod or iPad for free. The app offers the same features as a traditional light meter, and has undergone an upgrade since its initial design, which gives it better performance in low light. For a serious photographer, it’s an absolute must.
The Easy Release app gives you the tools to collect digital signatures with each photograph that you take.??Easy Release is made for the iPhone, iPad and iPod Touch, and integrates with each device’s built-in camera. If you shoot on a separate camera, consider taking a single shot with your iPhone, iPad or iPod for identification purposes, collect the model signatures in the app, and then just shoot freely with your external camera, knowing you have proof of your subjects’ consent safely stored.
http://digital-photography-school.com/5-great-mobile-apps-for-photographers