I can't say but I can tell you they can be quite different. I currently have 3 installed on my iphone:
Disneyland Wait Times, MouseWait, and Lines. Here's a sample of what they say right now, at 4:50pm DL time:
BTMM: DLW 35, MW: 45, Lines Posted 35 expect 29, reported closed at 3:25
Indy: DLW 55, MW 55, Lines posted 70 expect 57
Splash: DLW 100, MW 120, Lines posted 90 expect 75
Haunted Mansion: DLW 25, MW 25, Lines posted 30 expect 25
Little Mermaid: DLW 20, MW 20, Lines posted 10 expect 7
RSR: DLW 120+, MW 120, Lines posted 140 expect 113
Soarin: DLW 35, MW 45, Lines posted 50 expect 39
TSMM: DLW 50, MW 45, Lines posted 70, expect 57
Would be interesting to hear from someone there now how accurate these actually are.
I would add that while going through all these, neither Lines nor DLWait bugged me with annoying pop-ups, but MW did continually, often taking several attempts to X out before being successful. I have free versions of all 3 and assume there are paid available.
I've used Lines in the past and have been pretty happy with it.
There's also that number you can call in the parks that will give you the official DL posted wait times from Disney. I don't remember what it is but I'm sure someone will have it.