I have 3 WDW apps on my iPhone right now
"Park Hours"
"Wait Times"
"Undercover Tourist"
The first two I was able to use last month while I was there. "Park Hours" was excellent---we could see all the parks hours, EMH, and parade and firework times. They also have all the shows in World Showcase and their times listed as well as show times in the AK. Wonderful tool!
"Wait times" was fairly accurate, nothing we'd base our day on, like others said, it's user generated. It was just fun to play around with once we got in line. I did have some trouble with it accepting my time updates.
"Undercover Tourist" was free last week, so I downloaded it, but haven't gotten to use it in the park yet, but it looks awesome. It has park hours, wait times, a place to take a picture of the back of your ticket and store it for safe keeping, full menus with prices (which is awesome for deciding where to eat!), phone numbers of all the resturants, park maps with an area for turning on/off which features you want to see displayed on the map (age filters for rides, fastpass, resturants, smoking areas, etc), a way to see which rides/resturants are closest to you, a place to store favorites (with a way to "check off" what you've done), a place to plan your trip and save your itenerary, and a simple "memory" game to play while in line.
Lots of features---I got it for free---but it almost makes the $3-$4 that the app may be worth it.
My fiance also has the "uPinPoint" Disney maps---it's all 4 parks, water parks, DTD, and a few hotels. Its nice for the amount of maps it has, but I still think the Undercover Tourist app is more comprehensive. This app does have resturant menus, but it links you to allearsnet for them.
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I'd love to hear reviews on the official Hidden Mickey app. I so wanted to buy it, but it seemed expensive for what it was. Was all the HM's from the book in the app? Is there pictures of them if you can't find them? I submit it as my "wish" to Free App A Day all the time, but it hasn't come up yet!