Right, WDW lists their wait times strategically, where TP lists the wait times factually.The TP lines app is almost always more accurate. WDW tends to overestimate the wait time, on purpose. Right before park close (when you wouldn't need the TP app anyway), WDW raises the wait time really high to discourage people from getting in line. Generally speaking during most of the day, the WDW posted times run 10 or so minutes higher than it really is, but no guarantee. Even TP Isn't perfect, but it's fairly close.
That's the only thing we use TP for, the rest of it is garbage, IMO.