Nathan Myhrvold's six-volume foodie encyclopedia, Modernist Cuisine, writes reader SmartAboutThings, is one of the most expensive cooking encyclopedias, the original six-volume version retailing for $500, with the two-volume addition that followed after that selling for $115.
"Now, Nathan and his team have transformed their huge food encyclopedia into an iPhone/iPad app. It's not just a digital book, but rather an expensive $80 interactive app that can do more than just provide recipes. The interactive digital cookbook is the fruit of a development team of 10-15 people that have worked over nine months on the project. The app contains 37 technique videos, 416 recipes and 1,683 photos."

https://itunes.apple.com/us/app/mode...mt=8?at=11l4Kw