Project Catalyst is in the same spirit as iMessage and Apple's notes app, which sync between your iPhone ( $899 at Amazon) and your computer. This is an instantly appealing idea because it means that instead of installing duplicate apps on your iPad and on your Mac, you can download the same across multiple devices. Project Catalyst - previously referred to as Marzipan - is a piece of software that Apple's been working on that will make it possible to install and use your favorite iPad apps on your Mac. As expected, Apple announced Project Catalyst Monday at WWDC, its annual developer conference.