I have:
- 'WDW Dining Disney' - a really handy app for looking at menus. Very useful in planning my trip and will probably be useful in the parks (when deciding where to eat lunch etc.)
- All four park maps (called 'Magic Kingdom Mini Guide' etc.) - interactive maps, can be used to locate where you are in the park. In reality, probably of little use as the paper maps are more handy and I don't usually get lost!
- 'Disney World Wait Times' - I think that this is a fairly new app. Shows the wait times at the different attractions and the Fastpass return times. HOWEVER, it relies on users to submit the wait times so time will tell whether lots of people start using it and it becomes fairly up-to-date and accurate or not. This is one to keep and eye on. However, you would have to have data roaming turned on to use this in the parks (so keep an eye on how much data you're downloading).