You’ve probably mastered your favourite built-in iOS apps such as Camera and Safari. But other apps that come preloaded on your iOS device include features you may not have discovered.

Voice Memo

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. And remember, you can use your ringtones for other audio alerts besides incoming phone calls.

Fire up the app and record your new ringtone. Once you’ve finished creating 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 happy with your recording, tap the Share button, and then Email.

Trim your memo as necessary, and then email it to yourself for the quick extension trick that converts your recording into a ringtone

Download the recording on your Mac or PC. 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 on to iTunes, and the software will now recognise it as a ringtone, which you can in turn sync back to your iPhone.

Clock

You’ll 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, the app has a secret feature up its virtual sleeves: you can use it as a sleep timer for your music (or a video).

If you choose Stop Playing, the timer silences your iPhone, instead of ringing out, once time’s up.

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 the Stop Playing option.

With this selected, your iOS device will stop whatever music or video is currently playing when the timer runs out.

Calculator

A surprising number of iPhone users don’t realise that the built-in Calculator app actually offers a scientific calculator, too. To access more advanced functions, simply rotate your iPhone from portrait to landscape mode.

Stocks

The Stocks app is another one that offers an alternative 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 anywhere from one day up to two years. Tap and hold on the chart in that view, and you can drag your finger to see exact stock prices on specific dates. Swipe across the entire chart, and you’ll advance to the next stock on your list.

Tap and hold on the landscape Stocks interface to pinpoint exact stock values

Weather

Tap on the Weather app’s interface, and you’ll expose an hourly breakdown for the rest of the current day’s forecast. And don’t forget you can swipe on the current weather conditions in Notification Center to show the five-day forecast instead.