App Chef is for developers who don't use Xcode and want to combine two or more apps to make a universal app. The first app (the actual app, not the binary in the ./Contents/MacOS/ folder) dropped in is the app that will be over-written after clicking on the "Create" button. This way you don't have to create a new app folder and put your resources, plist, and more back in. It supports Intel 32, Intel 64, PPC 32 and PPC 64 architectures. App Chef itself is a universal binary that supports both 32 and 64 bit OS.