If you're interested in Expo/Dev for iOS, be sure to visit large format photographer David Jade's blog Flux and Mutability for updates and articles on the app's features.

Here's a snippet, with a series of other articles to follow soon:

"ExpoDev has many unique features that you won’t find anywhere else, such as calculating exposures based on personal film test data, the only exposure calculator which applies reciprocity adjustments that are based on actual lab-produced film tests for a multitude of film and developer combinations..." -- David Jade