Below are instructions to retrieve IP address of your router on any iOS device.

• Unlock your iOS device
• Navigate to home screen by tapping on home button
• Tap on "Settings" app. Typically it is at the bottom list of the apps but it also could be in other location within app list
• In Settings app look for Wi-Fi and tap on it
• You should see list of available Wi-Fi connections. Active Wi-Fi connection will be marked with checkbox.
• Tap on active Wi-Fi connection
• Look for line with "Router" in it. This line will have your router IP address