The official disneyland app. I've tried 2 other ones and they both depended on member's to input current wait times and current FP returns which means it can be inaccurate if no one has logged in to update those times. The DL app goes off of their computers so it reflects what you see at the stand-by or FP return times.
If for some reason this link does not work, just go to your iphone app store. For Android, the play store.
Also, may go to Disneyland's website then guest services then scroll down to Disneyland Mobile App.
The Disney app could use some fine tuning.
The last time we were in the parks there were 2 rides that kept coming up with wait times even though they were closed - and we were updating their status to show it. It seems like people form other locations in the world may be inputting times for what ever reason. Disney needs to disregard or give lower priority to those that block their location or obviously aren't there and give more weight to those that identify as being in the park and actually in front of the attraction.
But overall it's a pretty good indicator and a useful tool.