June 09, 2012, 7:50 AM — You’ve probably mastered your favorite built-in iOS apps, like Camera, Mail, and Safari. But other apps come preloaded on your iOS device, and they include some features you just might not have discovered yet.
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You already know that the Clock app can show you the current time in countries around the world, schedule alarms, set timers, and work as a stopwatch. But despite its utilitarian focus, Clock has a secret feature up its virtual sleeves: You can use it as a sleep timer for your music (or a video).
If you want to fall asleep to the musical strains of your iPhone, launch the Clock app and tap on the Timer tab. Underneath the dials for setting the hours and minutes for your timer to run, tap on the When Timer Ends button. Normally, you’d use that control to choose which of the iPhone’s many sounds should ring out when your timer reaches zero. But scroll past all the sound effects, and you’ll find one option sitting by its lonesome: Stop Playing.
With Stop Playing selected, your iPhone (or iPod touch) will automatically stop playing whatever music or video is currently running when the timer runs out.
A surprising number of iPhone users don’t realize that the built-in Calculator app actually offers a scientific calculator, too. To find it, just rotate your iPhone from portrait to landscape mode.
You can use the Voice Memo app to make short recordings for yourself. But you can also use it to create custom ringtones, with relatively little effort. Fire up the Voice Memos app and record your new ringtone (and remember, you can use your ringtones for other audio alerts besides incoming phone calls).
Once you’ve finished recording your masterpiece, email it to yourself: Tap the list button at the bottom right corner to get to your list of memos. If you want to trim the recording, tap the right arrow to get to the Info screen and then tap Trim Memo. Once you’re content with your recording, tap the Share button, and then Email.
Download the recording on your Mac. It will sport the .m4a extension. Rename the file to so that it instead ends with .m4r. Double-click your new .m4r file, or drag it onto iTunes, and the software will now recognize it as a ringtone, which you can in turn sync back to your iPhone.
The Stocks app is another one that offers an alternate view when you rotate it into landscape mode. You’ll see a wider chart of stock price over time, and you can adjust the charts range from one day up through two years.