iPhone incorporates these accessibility features:
Turn on accessibility features. Go to Settings > General > Accessibility, or use the Accessibility Shortcut. See 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 click Configure Accessibility at the bottom of the Summary screen.
For more information about iPhone accessibility features, see www.apple.com/accessibility.