Scannable is Evernote's entry into the mobile document scanning world, and it looks impressive. The interface is simple, scanning is a breeze, and sharing documents to Evernote, other cloud storage platforms, and via email is intuitive.
What it has in simplicity it lacks in specificity, however. There aren't any markup options, and looking at all your documents is tedious: you actually have to scroll through them like a photo roll.
The lack of deep features makes it obvious that Scannable is a companion app for Evernote rather than a stand-alone tool. Still, if you need simple scanning that's intuitive you'll likely benefit from the app.
You can get Scannable on iOS.