OmniFocus 2.7 for iOS introduced a native Apple Watch app (with watch face complications and a customizable glance), along with support for major new iOS 9 features such as split-screen multitasking and integration with system-wide searches. It also added support for pasting multiple actions at once from other apps such as Notes.
Apple released watchOS 2 on September 21st 2015. As the OmniFocus 2.7 native Apple Watch app replaces our original Apple Watch application, watchOS 2 is required to install the new application on your Apple Watch. If OmniFocus 2.7 for iOS or later is installed on an iPhone paired with an Apple Watch running watchOS 1, you will temporarily lose access to the OmniFocus for Apple Watch application. The new OmniFocus for Apple Watch native application can be installed after your Apple Watch has been updated to watchOS 2.