iOS makes smart use of the Home button. You can double-click to switch apps, and even triple-click to do all sorts of things. The speed at which you need to click the Home button to register a double- or triple-click is fine for many people, but if you find yourself struggling to click the button fast enough, you can slow things down a bit.
To get started, fire up your Settings app and tap General.
On the General settings page, tap Accessibility.
On the Accessibility page, scroll down near the bottom of the list of settings and tap “Home Button.”
You have three options for your Home button click speed: Default, Slow, and Slowest. Slower speeds allow more time in between clicks when you’re double- or triple-clicking the Home button. When you make a selection, your device will vibrate three times to show you the speed required for multiple clicks. Choose the one that works the best for you and exit the Settings app.
And there you have it! It’s a simple change if you know it’s available and where to find it, but changing the click speed for your Home button can make a big difference if, for whatever reason, you’re not able to click rapidly enough at the default speed.