Lots, apparently. Among the All Time Top iPhone Apps on 148App', Stanza is the only e-reader to show up. Some would undoubtedly see the low ranking of e-reader apps as a negative, which a sense it is. But consider the potential, with all the zillions of iPhones out there, and also remember that about 10,000 App Store offerings exist. So even now it isn't as if e-books have been a bust on the iPhone---far from it. Also, I suspect that eReader is probably among the top several hundred apps. Anyone care to check this out?
How e-books could hit it truly big on the iPhone
Improvement of program interfaces---with completely seamless Kindle-style shopping and downloading---could make a dramatic difference. So could the availability of more titles, which we know will be coming from major publishers such as Random House and Simon & Schuster.
Tip: Use 148Apps’ search engine to search for new iPhone apps, although it’s far from perfect. When I typed ereader and e-reader, I couldn’t see Stanza or eReader. Could eReader be missing because the search is just limited to the top 148 apps? Remember, meanwhile, that the App Store has its own search engine, both on the iPhone and within iTunes.
Keeping up with new apps: You can use RSS and Twitter to monitor newly released apps.
Detail: FlipBook Lite is also on the list, but isn’t for book reading, as best I can determine.