Software like this is going to work wonderfully for some people, and horribly for others, depending upon how specifics of the implementation meshes with the users' work styles. This is the sort of software where a user is going to need to try several different applications before settling on one.
To offer it only the in App Store with no demo, for a non-trivial price, has at least caused me to look elsewhere, especially given the occasional didn't-work-for-me reviews there.