Josh Clark is a designer, developer, and author specializing in mobile design strategy and user experience. He's author of the O'Reilly books Tapworthy: Designing Great iPhone Apps and Best iPhone Apps: The Guide for Discriminating Downloaders. Josh's outfit Global Moxie offers workshops and consulting services to help creative companies build tapworthy mobile apps and effective websites.

Before the interwebs swallowed him up, Josh worked on a slew of American public-television programs at Boston's WGBH. He shared his three words of Russian with Mikhail Gorbachev, strolled the ranch with Nancy Reagan, hobnobbed with Rockefellers, and wrote trivia questions for a primetime game show. In 1996, he created the uberpopular "Couch-to-5K" (C25K) running program, which has helped millions of skeptical would-be exercisers take up jogging. (His motto for fitness is the same for user experience: no pain... no pain.)