Two other apps that I have been testing lately are Moleskine and Pento. I wouldn't advise paying for either of these as they are clearly still works in progress, but they both have good-looking interfaces and look promising.
To a notebook addict like myself, seeing the name Moleskine
on an app is of course very exciting. And since the app is (for now) free, I lost no time in giving it a try. The app is visually very pleasing and does look like a Moleskine notebook, but there is still a lot of work to make it useable. The app is excruciatingly slow and a bit buggy. Handwriting is not very good but sketching is OK. iOS auto-correct does not work on the type tool, which is a big problem for me (in French, since the accents are not on the iOS keyboard, auto-correct is essential to fill them, otherwise typing is slow and cumbersome).
is sold for $2.99, but I would not recommend paying for it just yet. However the app is regularly offered for free, and that's how I got it. There is also a Pento Lite apparently, which I didn't try. I really like the look of the app. It has a "grabber" function that you can use to copy a web page to your notebook (as an image) and annotate it. But like Moleskine, it still needs a lot of work. The interface is sometimes clumsy or annoying (no undo button but a gesture which I can't be bothered to memorize) and essential functionalities are missing (auto-correct again). I don't see a lot of upgrades though, so I have to wonder if it will ever get to be worth the price asked. I hope so.