Craft is a meticulously-designed note-taking app for iPhone, iPad, Mac, Windows and Web. It's well integrated with OmniFocus and is a great place for reference information and project support notes, whether you're using it individually or as part of a team.
Hookmark for macOS makes it possible to link your OmniFocus projects and actions to almost anything, including files, folders, notes, websites, and emails. Having what you need within easy reach accelerates the process of getting things done.
