Let’s face it — most of the wares in the iPhone App Store are not exactly killer. Many are useful. Many are fun. Many are worthy of taking up space on one’s smartphone. But Apple itself took care of most of the truly essential applications, the ones people really buy an iPhone for — the Safari browser, e-mail, an iPod, YouTube and Maps. Almost everything else is at best a nicety. Maybe it’s worth a couple of bucks, and plenty of people may well download it if they happen to discover it in passing.