Microsoft also announced it will be opening up a cloud API for OneNote, allowing developers to integrate other apps with the software. You can also add notes to your saved files to ensure you don't miss a thought. OneNote allows you to take snippets of information from content such as web pages, take snapshots of documents or whiteboards and save all these in one place. The application was previously available on PC, Windows Phone, Windows tablet, iPhone, iPad, Android phone and via a web experience. OneNote has arrived on Mac and will be available for free across platforms, ending weeks of speculation that an Apple-friendly version of the note-taking software would soon surface.