We just returned from Disneyworld yesterday and used the following apps quite a bit while we were there:

WDW Dining (menus with prices)
TWiz (transportation tips for getting places)
WDW Maps (even had a map of the Orlando airport)
WDW Times (time schedules for park opening and closings and show times)
eTicket WDW (wide variety of information)

Now if ONLY Intercot would develop an App...it would be wonderful! It is my favorite and most used Disney discussion website by far....I rarely visit any other websites.