Select text in any Mac app and PopClip pops up with instant text actions. Install the OmniFocus extension and you'll be able to send selected text to OmniFocus.
Focus is a flexible productivity timer with built-in support for OmniFocus. Define your work in OmniFocus and use Focus to help you bring it to fruition.
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.
DEVONthink is a powerful data storage and research app for Mac, iPhone, and iPad that's a natural complement to OmniFocus. Through the use of links, you can have a vast amount of data at your fingertips as you work on tasks in OmniFocus.
IFTTT (If This Then That) is a web-based service that can be used to automatically trigger the creation of OmniFocus actions based on a wide range of conditions.
An alternative to Apple's Calendar app for Mac, iPhone, and iPad that provides enhanced functionality, a natural language interface, and OmniFocus integration.
