Your iPad didn't come with a clock app, but for $3.99, Clock Pro HD offers tons of useful features and a very attractive interface. Along with the usual options like timer, stopwatch, world clocks, and alarms, you can also check the sunrise, sunset, and tidal times at your current location, use it as a chess clock (two clocks counting down alternatively, based on who’s playing), and even a metronome.

Find My iPhone (free, universal) is an invaluable free tool. Once your iPhone, iPod touch, or iPad is registered, you're all set. Then if your device goes missing, you can use a Mac, PC, or any other iOS device to locate your lost hardware on a map. If it's right under your nose, you can have it emit a loud beep to help you find it, or if you fear someone’s stolen it, you can even wipe your device’s data remotely.

Living Earth HD ($0.99, universal) is as useful as it is beautiful. It'll show you a gorgeous image of the planet, including current cloud cover. You can swipe it to see other parts of it, and pinch to zoom in. It'll also tell you the local time, temperature and weather forecast in as many cities as you like. And the single alarm can wake you to your favorite song.

USB Disk Pro ($2.99 for iPhone or iPad) lets you use your device as a portable hard drive. You can add files via a tethered iTunes sync, or email files to yourself and use Open In to add them to the app. The app lets you preview, copy, or delete files; attach them to new emails; copy text to use in other apps; or create a new file from the clipboard contents.

Your iPhone and iPod touch have a built-in audio recording app, but Recorder Pro ($0.99, iPhone) goes further. One of its best features is voice activation, which means that you won’t be wasting precious storage capacity recording long pauses. You can also choose various formats, compressed or uncompressed. Once done, you can rename your recordings, organize them into folders, and export them via iTunes.

Use your device’s camera as a scanner, thanks to Scanner Pro ($6.99, iPhone). Take a photo of each page, and the app converts them into a multipage PDF document. You can grab a shot straight from the app itself, or from your camera roll. Once imported, you can crop and straighten the image to get the best possible fit, and even alter the brightness and contrast to help make the words stand out as much as possible.

Dragon Dictation is a free and very clever universal app: It converts anything you say into editable text. Its only drawback is that your device needs to be online, as it sends your recording off to a server to analyze and transcribe your words. As with any voice-recognition app, the results aren’t 100 percent accurate, but they’re still extremely good considering no training is required.

Your iPhone and iPod touch come with a calculator, but strangely, not the iPad. Our favorite calculator app is Calculator+ ($0.99, universal). On iPhone and iPod touch, it offers a visual display of your scientific or basic formula so you can check if you made a mistake along the way. On the iPad, there’s also a section for you to write down notes which can be exported and used in other apps.

Have you ever needed a reason to get out of a boring meeting, awful blink date, or dull party? Have no fear, Fake Conversation is here! This free iPhone/iPod touch app will actually call you. If you’re adept at faking a phone conversation, that’s all you’ll need, but if you require a little help, you can choose from a long list of “excuses” (some free, most paid). Just repeat back what you hear, make your apologies, and escape!

Universal app Screens is $19.99, but for controlling your computers remotely, it’s worth every cent. It's visually attractive, letting you swipe through the various computers your iOS device has connected to in the past. And the touch input works great: you don’t have to drag the cursor to control a part of the interface: tap and it’s selected. It makes navigating a computer from your iPhone or iPad more pleasurable -- and fast.