The paper is subtly marked to allow the scanner app to auto orient and correct image layout and color. It's a nice idea and I'm sure it works great. I'd still prefer a better sketching and handwritten notes app on iOS. I'd really love to see an industry standard that can be adopted by paper manufacturers. Requiring a specific notebook and app is just too limiting for me.
That said, all of these are small steps towards better note-taking and digitization and I like that. I may give one or both a try. They are very similar but Whitelines looks like it provides more options for automatic processing of scans.