“Tapworthy: Designing Great iPhone Apps,” by Josh Clark, $39 from oreilly.com.
If you’re thinking of making money off an iPhone or iPad app, there are lots of things you may not have thought of. Most of them are in this book. What’s great are the first person accounts from successful iPhone developers, such as Josh Williams, founder of Gowalla, a popular social networking site. The developers discuss all the decisions they went through, from what colors to use to problems when people with wide fingers didn’t know they’d tapped an icon because they didn’t see it react. The same decisions and problems discussed here would apply to making apps for the new Android phones, though the Android is not directly addressed.