First, I’d like to note that this is not through the Mac App Store, this is through MacUpdate.com/Scrivener.
What is Scrivener? Scrivener is an amazing piece of software for writing e-books, as well as lengthy documents. It supports a large number of formats, and gives you complete control over every aspect of the formatting. It’s not a word processor, but it can easily take the place of a word processor. It’s focused on helping writers organized their projects. The developers behind it describe it as a “complete writing studio” and having used it for a few years, I can agree with that.
If you are a genealogist looking to put together a book on family history, I would highly recommend it. I’ve been meaning to put together some articles on using it in conduction with genealogy software.
You can try it for free through the official website.
To take advantage of the 50% off, you’ll need to purchase it through MacUpdate.com before May 8, 2014.