The app is pretty stunning, visually. You're asked to log in through your cable provider at the outset (though you can browse shows as a guest, too). From there, you're greeted with a moving wall of thumbnails. Movies, series, specials -- everything HBO has to offer through the app is right there. You can browser traditional menus if you want, but that's not nearly as much fun.
Pick a show, and watch. It's that simple. And it's about time.
We've got some quick hands-on video after the break if you prefer.