It's not the simplest app to learn. In fact, there's a relatively steep learning curve. Mind you, it's not like learning a new desktop publishing program on your Mac -- but for an IOS app, it's fairly complicated.
I'm still not all-in with the app. I have more help files to read. When and if I master the thing, I'll write it up here. But seriously, this may be the big-time writer's app. I lets you record your notes, clip web pages, draw on the page and on photos and PDFs, and there's a very natural To-Do system that, with little effort on your part, serves up a daily list of stuff that Must Be Done. It kind of happens all on its own, from sticking due dates on your to-do's. I was amazed by the functionality of the system.
BTW, there's an iPad app (for a mere two bucks) and there's also a matching Mac app (for five bucks). The two talk to each other and keep in sync, using iCloud, which makes them wildly useful. And you don't have to rely on a developer's site (i.e., hope that it will continue to exist after you've input your precious data). This is all on the user's end. I like that a lot.
That's it for now. I'm really hopeful about this one.