MDE, just because I want to be a contrarian.
OK, fine... I'd agree Lines is more accurate...assuming that at least one or two people have reported wait times recently. If it's been inactive (which is rare) for long stretches, then I found it to be lacking somewhat. However, most of the time it's pretty darn good.
Actually, I still like MDE as well. It's consistently inaccurate...if that makes sense. It's always conservative. So if it says 40 minutes, it's probably around 25-30.
However, regardless of which app you use, a lot of it has to do with how many FP+ come through while you're in queue. If a steady and consistent stream come through, then it's accurate. If none come through then you'll get on much quicker than predicted. If a flood comes rushing in, it'll take much longer. That's how we got on FEA less than 2 weeks after grand opening. MDE said 90 minutes, but Lines said 40. So we went for it. By luck, I guess, almost zero FP+ came through while we were in line. So it was boat after boat of standby...we waited less than 30 minutes.