Airmail
An email client that allows you to create OmniFocus actions that reference emails, manually or automatically using rules.
Drafts
Quickly and conveniently and capture text and then send it to OmniFocus and other destinations through the use of flexible, customizable actions.
Evernote
Evernote is a natural complement to OmniFocus. Use it to store ideas for upcoming projects and as a repository for project reference material.
Fantastical
An alternative to Apple's Calendar app for Mac and iOS that provides enhanced functionality, a natural language interface, and OmniFocus integration (Mac).
Spark
A polished email client for Mac, iPhone, iPad, and Apple Watch with a focus on email prioritization and support for teams.