Moglue is a new program, available for Mac and Windows, that enables you to create interactive ebooks and publish them to Android and iOS devices. Your ebooks created with Moglue can include videos, images, and audio files that you import from your computer. Moglue supports a wide variety of file formats for image and video content. When you have completed constructing your ebook you can publish it to the Moglue bookstore where it can be downloaded onto your Android or iOS device.
Clarify is an OS X app (a Windows version is promised, currently in a free beta period, that allows you to take multiple screenshots, annotate them, and combine them into a single document. This creates an easy-to-follow set of instructions for just about any task.