Select some text with pictures in ePub document and post it on Twitter right from Chapters using Share button in a window toolbar.
ePub documents should comply with a certain version of ePub standard, which is currently at version 3.1 Chapters can open virtually any ePub document, but when it creates new ePub documents they are with ePub version 3.0
It becomes more interesting when you open ePub document and begin editing it with Chapters. If document is under ePub version 2 or earlier then Chapters will upgrade that document to ePub version 3.0 by adding required metadata and navigational info to it. Similarly, when you open ePub 3 document and begin editing it, Chapters will add metadata and NCX to make document backward compatible with ePub version 2.0 This is the default behaviour of the app.