Learning With iPads offers this very useful post which offers apps to help develop reading by APP Assessment Focus. You will need to click through, as this is is a screenshot, to give an overview.
You should definitely visit Learning With iPads, to learn more about using them in the classroom and for app suggestions.
A superb site, which reviews and recommends useful apps for iPads, Android and web. Apps are searchable by subject area, age range or device. If it had an RSS feed, it would be absolutely perfect!
A definite must – do visit the iPad apps page or the main site.