All iOS devices come with a triple-click home button gesture that can launch what are known as accessibility shortcuts. These shortcuts can work wonders for folks that are hearing impaired or have problems with their vision, but they have everyday uses too, as they offer innovative ways to interact with your device.

Accessibility shortcuts are not enabled by default, which means it's up to you as the user to activate them. So if you'd like to solve issues with color blindness, hearing trouble, or bad vision, or just want to lock your kids out of certain areas of your iPad, iPhone, or iPod touch, I'll show you how to fully customize this feature below in iOS 9.

To assign an accessibility shortcut to the home button triple-click gesture, start by heading to the "General" entry in your main Settings menu. Tap on "Accessibility," then scroll down towards the bottom and select "Accessibility Shortcut." Use the following menu to select any shortcut you would like to use.

Once you've done that, you can trigger any accessibility shortcut by triple-clicking your home button, and you can toggle the feature back off by triple-clicking again.

With options like VoiceOver for the hearing impaired, Grayscale for those with color blindness, Zoom for anyone with sight issues, and AssistiveTouchfor those with broken home buttons, having one of these shortcuts assigned to such a simple gesture is quite helpful.

You can even use some of these shortcuts for things you never thought possible. For instance, by altering the Zoom settings, you could turn the shortcut into a brightness toggle. That, in turn, would allow you to adjust screen brightness below the default settings. You could even use the AssistiveTouch shortcut to take hands-free Snapchat videos.

Thankfully, iOS doesn't take an all-or-nothing approach with its accessibility shortcuts, which means you can choose to have multiple shortcuts triggered by the triple-click home button gesture.

The way this works is simple—just head to the same Accessibility Shortcut menu, then select as many of the shortcuts as you'd like. From now on, when you triple-click your home button, you'll see a menu asking which accessibility shortcut you'd like to launch. Just select the shortcut you'd like to use at this time, and when you're done, triple-click your home button again to toggle the shortcut's features off.

There's one more feature you can assign to the triple-click home button gesture on iPhones, but this one's less about accessibility and more about preventing other people from accessing certain parts of your phone.

So if you have nosy friends who like to swipe through your gallery when you're trying to show them a single picture, or if you have young children who occasionally play with your phone, start by heading to the "Accessibility" menu in Settings under General. From here, enable the "Guided Access" option, which can be triggered at any time using the triple-click home button gesture.

(If you have other shortcuts enabled, you'll have to choose Guided Access on the shortcut picker.)

When you activate Guided Access, you'll see an interface that allows you to select areas of your screen that you don't want other people being able to touch, and you can also press the "Options" button to disable a few more things. Once you've done that, press "Start," then you'll be asked to enter a PIN that will be used to exit Guided Access mode later.

At that point, you'll be able to hand your phone over to the other person without worries, because the only way for them to exit this app or interact with the restricted area would be to triple-click the home button (and tap on Guided Access, if other shortcuts are enabled), then enter the password you set earlier.