Originally published on metropolis.co.jp on November 2010

What’s the difference between chu-toro and akami? How do you tell whether your aka-gai is fresh? What’s the best season for enjoying suzuki? With the new Sushi Book iPhone application (¥450), you can get all these answers on the go. Based on a guidebook from Shinjuku-based publisher Japan Travel & Life, this handy app contains a directory of 20 kinds of sushi neta (toppings), with pictures, bilingual explanations and a pronunciation guide covering aoyagi, uni and everything in between. There are also sections on the history, tools and techniques of sushi, plus a restaurant guide divided into high-end, chain and kaiten-zushi joints.

See www.jptl.jp/en for details. To mark the release of the iPhone app, Japan Travel & Life is offering ten lucky Metropolis readers a copy of the original print book. See www.metropolis.co.jp/giveaway for details