Hi Kathryn!
I have several (ahem...maybe more than several) apps on my phone that I like. You can get some pretty good ones for free (yaaaay!) and others will cost you. Some of the best ones will show wait times for attractions, and provide park maps that are just a touch away!
One of my favorites is Disney World by Undercover Tourist. It provides park hours, wait times, parade times, maps, restaurant info (including menus)--and all of that is FREE! You can upgrade to the full version, but I've found with the free one, I get all I really need.
One of the best reference apps is from our own Moms Panel Member,
Doug! It has park maps, detailed attraction information, planning guides, resort reviews, and much more! It's like carrying Doug along with you in the parks (except with the app you don't have to feed him snacks and buy him souvenirs every 2 hours)!
Have a magical vacation!
Amanda