My iPad is the first Apple product I've ever owned, since I started out with PCs. I'm finding it hard to adjust to the difference. My present problem is with apps...mainly installing them. I've (tried to) install an eBook reader and (tried to) install the Facebook app. Both times, when I pressed the "install app" button, a hazy light black square displayed on the screen. Is this the Apple equivalent of Windows' hourglass or revolving circle indicating that something is happening?