Disneyland has an official app. It worked very well for us this last trip, I had problems with it before but I think it had more to do with my carrier than the app itself.
Either way, it's just called Disneyland and it has a blue icon
I also like the Official Disneyland App. It gives you wait times, current FP return times, etc. In my experience the listed times match pretty well to the times posted outside the attractions; there might be a 5 to 10 minute delay in updating the information on the app, but it's pretty good.
Other than that, there are a number of free wait time apps, but they usually rely on guests inside the park updating the wait times. I've used MouseWait and DL Wait Times. Both were fine, but work best when lots of guests are updating the wait times.
All APPs other than Disneyland are user apps and wait times are only as good as the users inputting the info. If noone is updating it, then the information can be outdated and not useful.
All APPs other than Disneyland are user apps and wait times are only as good as the users inputting the info. If noone is updating it, then the information can be outdated and not useful.