Ginger Labs
Notability
FreeWelcome to Notability: powerful, yet wonderfully simple note-taking and PDF annotation.
iOSTwobird
FreeYour all-purpose inbox.
iOSNotability
PaidNote-taker to annotate documents, sketch ideas, record lectures, take notes and more.
MacTwobird
FreeWelcome to Twobird, a new kind of email app that includes all your everyday tools.
Android