You can do a lot of great things with just an iPad, but one of the best options is to use it as an external controller for your computer. From using your iPad as a second display to turning it into a remote, here are some ways to augment your computer with an iPad.
Use Your iPad as a Second Display
It's still debatable whether or not a multiple-monitor setup is productive or not, because it really boils down to what kind of work you do. However, an iPad makes an excellent extension to your monitor if you don't have a lot of space.
You have a bunch of different options to turn your iPad into a second display, but we prefer Air Display. It allows you to install the app on your iPad and another on your Mac. After a reboot, you'll be using your iPad as a second display within minutes. For a little more customisation and power, Splashtop XDisplay is another great option that works more smoothly than Air Display, but the setup process isn't as intuitive.
Turn Your iPad into a Keyboard Shortcut Machine
Even if you have a grasp on the basics, certain programs have so many shortcuts and actions it's impossible to remember them all. If you want to extend the reach of your computer's keyboard to your iPad, you have few really solid options.
If you want to just test out if this is a feature you'd want, HotKeys is an app that allows you to easily control and use shortcuts on your iPad to control your Mac. It's a little awkward to set up, and it's not foolproof, but once it's running you can create sets of shortcuts that work in specific applications that are all accessible on your iPad.
For power-users, we like Actions for iPad ($4.49), because it can do most things. Want to just use it for quick access to hot keys? That works out of the box. Want to add specific action buttons, like "New Tweet" or "Quote Tweet" to Twitter? You can do that too. In fact, you can customise all sorts of actions, including hotkeys, snippets, control media, move windows, control the system and even open specific web pages. It take a little while to set the whole thing up, but once Actions is running, it's like having a super-powerful extension to your keyboard.
Finally, if Photoshop is all you really care about, then Adobe Nav for Photoshop allows you to get quick access to all your Photoshop actions in one place on your iPad. It's not perfect, but it's worth checking out if you're a frequent Photoshop user.
Use Your iPad to Remotely Control Your Computer
Remote control apps shouldn't be that exciting, but controlling your computer remotely with your iPad is one of those experiences that's pretty exciting to do no matter what. You have a lot of options here to do remote control.
We like Screens as one of the better options. With it, tapping into your computer remotely is easy, and you get full multitouch control when you're in. Essentially, with little setup, you'll have complete access to your home computer from anywhere on your iPad.
Use Your iPad a Trackpad or Remote
Not surprisingly, you have quite a few options for turning your iPad into a trackpad, mouse or remote control for your computer. We have a few options for doing this we like depending on exactly what you're looking for.
If you're looking for a general purpose trackpad, we like Mobile Mouse. On a basic level, Mobile Mouse turns your iPad into a trackpad mouse with multitouch, but it's also an application launcher, file browser, media remote, web remote, presentation remote, numeric keyboard and more. Essentially, it turns your iPad into a smart trackpad that can also operate as an extension to your keyboard.
For a slightly different experience, we like JumiDesktop+. Alongside a similar set of remote control features, JumiDesktop+ turns your iPad into something closer to a mouse, as well as a keyboard, a remote desktop and lots more. iPhone users looking for a similar program will also want to check out HippoRemote Pro.