As we've already seen in our in-depth review, online and social connectivity is a big part of the PlayStation 4 experience. And a key part of that is the companion PlayStation App.
The free app allows you to access PlayStation Network features when you're away from your console -- or, for that matter, when you're sitting in front of it. You can browse your friends list and see what everyone's playing, compare trophies and see recent activity. You can also chat with friends, receive notifications, game alerts and invitations, and even use the app as a wireless keyboard for the PS4. If you're in the mood for shopping, you can browse PlayStation Store, buy games and DLC and set them downloading remotely. And for those of you who miss manuals, you can access all the system guides, game manuals and the PlayStation Blog from the app.
The app also supports second-screen features, though games must be specifically designed to support this functionality -- no Remote Play support here, though would you really want to play a console game with a touchscreen?
Neither version of the app is optimized for tablets at present, so you're best off downloading it to your phone. Note that you will, of course, require a PlayStation 4 in order to make use of the app, so it probably won't be all that useful until the console is released on Friday. Still, if you want to make sure you're as ready as you possibly can be, download the app here for iOS, here for Android.