Mac: If you've ever wished you could test drive Android apps on your Mac, BlueStacks is a new piece of software currently in alpha that lets you do just that.
BlueStacks was released for Windows last year, and the Mac version is similar. It's still in alpha with only 17 apps supported, but more are supposedly on the way. When you load up BlueStacks, you'll get a window where you can download new apps or launch what you already have. Click them and they run just as they would on Android.
If you like, you can also sync what you do in BlueStacks on your Mac to your Android with BlueStacks Cloud Connect. BlueStacks is still in beta, but I didn't have any trouble with the apps I tested. It's a free download from the developer's site.