Turn on accessibility features. Go to Settings > General > Accessibility, or use the Accessibility Shortcut.

Use iTunes to configure accessibility.You can choose some accessibility options in iTunes on your computer. Connect iPhone to your computer and select iPhone in the iTunes device list. Click Summary, then clic Configure Accessibility at the bottom of the Summary screen.

Choose the features you want to control. Go to Settings > General > Accessibility > Accessibility Shortcut and select the accessibility features you use.