The Disney Parks Mobile Magic app is free, even to non-Verizon customers. You just have to have a compatible smartphone. I used it on my AT&T iPhone earlier this month. The wait times and Fastpass return times were spot on. But those features are not unlocked until you are in the park where the attraction is located. So, you cannot get a Fastpass return time for Soarin' if you are in the MK.
There are other apps that have both free and paid versions. They all work somewhat okay but none of them were as accurate as the official Disney app.