Apple settings app

prefs

Open the preference / settings app.
You can open the app at different pages

Application homepage: http://www.apple.com/iphone
iTunes link:
HTML Link example: <a href="prefs:root=AIRPLANE_MODE">Switch to airplane mode</a>
Native application URL string example: prefs:root=General&path=Bluetooth
Extended example:
Tags: settings preferences

Airplane mode: prefs:root=AIRPLANE_MODE
Bluetooth: prefs:root=General&path=Bluetooth
Brightness: prefs:root=Brightness
Location services: prefs:root=LOCATION_SERVICES
Location services (System services): prefs:root=LOCATION_SERVICES_Systemservices
Hotspots: prefs:root=Hotspot
WLAN: prefs:root=WIFI
UMTS-Settings: prefs:root=General&path=Network
Mobile data: prefs:root=General&path=USAGE/CELLULAR_USAGE
VPN: prefs:root=General&path=Network/VPN
Sound: prefs:root=Sounds
Rigntone: prefs:root=Sounds&path=Ringtone
Siri speech settings: prefs:root=General&path=Assistant

(Thanks to Ammi through Pastebin.com)