Like OneNote and Evernote, you can add audio annotations to files in Notability. However, audio recordings can make Notability documents difficult to share with other apps. For example, I imported a document with an attached voice recording into Evernote, and it saved as a Zip archive, which I couldn't open.
You can delete a portion of a document in Notability by tapping its scissors icon, and a text tool lets you add typewritten annotations.
You don't need an Apple Pencil to hand-annotate documents in Notability or these other apps, but the stylus lets you draw more precisely. If you're looking for an alternative stylus that works with the iPad Pro and other devices and is a bit more affordable, check out FiftyThree's Pencil ($50 to $60).
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