How well do you really know your iPhone?

The basics are easy enough to figure out, but WSJ tech writer Katherine Boehret finds that many of us aren't aware of the shortcuts. Did you know, for example, that instead of using your finger to scroll up to the top of a page you can tap the status bar - that's where the time and battery life are displayed - and it will get you there immediately. When entering an email address, hold down the period key to see other address endings. Also:

The iPhone and iPad have many apps running in the background. There are shortcuts for jumping around apps without going to the home screen. Double tap the Home button (a physical button below the screen) to see a pop-up tray of apps and swipe to the left to scroll through them. Select one to jump to it. On the iPad, do this is by placing four fingers on the screen and swiping all of them up at once. This and other multitask gestures are on by default on the iPad 2 and newest iPad. But you have to turn them on with the first-generation iPad by going to Settings, General, Multitask Gestures.

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The same button on the right edge of your iPad that locks the screen in portrait or landscape mode can double as a mute button. This comes in handy if you find yourself frequently muting the iPad. Change this button's default lock function by going into Settings, General, Use side switch to: Lock Rotation or Mute. By default, this button is on Lock Rotation. Another quick way to mute is by pulling up the multitask bar by double tapping Home (or using a four-finger swipe up), then swiping left-to-right to see a mute, as well as sliders for volume and screen brightness.