Unless its changed, Disney Mobile Magic was only available from Verizon (There are ways to use it on other carriers though- google) and it has the official wait times and FP times in the park you are in. Other parks you aren't in just says Moderate or Available now, etc.
Lines gives the estimate based on their data, but has the option to post from users and you can see what folks post. I've not had issue with either. I use DMM to get the accurate times, and use Lines if I want to see what folks recently have been reporting.