i assume that if the app is generating a plan, then there is some qualifed input from someone who understands coaching/training. for example how does it decide how many 'race days' are enough, or whether two back-to-back long runs are inappropriate?
as the other thread says, i did it in 2010. difficult to say whether it's easy or hard to get into. i know a few who did and a few who didn't. if you can make though, you should. the whole experience is the nuts.