How do I setup Wi-Fi calling on my cellular phone?

How to setup Wi-Fi calling on a cellular phone:

 IOS Devices
  1. Go to the Home Screen.
  2. Tap Settings.
  3. Tap Phone.
  4. Tap Wi-Fi Calling.
  5. Tap or slide Wi-Fi Calling On This iPhone. (slider will be green)
  6. Tap Enable
  7. Follow the onscreen instructions to enter a US address for use in the event of an emergency call (911).
    1. When setting up the location for the emergency 911 settings, please enter the address for the location you are most likely to be while using the Wi-Fi calling feature.
 Android Devices
  1. Follow these steps to activate HD Voice. Skip this step if it's already activated.

    1. Go to the Home Screen.
    2. Open your Apps menu.
    3. Tap Settings
    4. Look under 'Wireless & networks' section.
    5. Tap 'more...'
    6. Tap Cellular networks
    7. Turn on Advanced Calling
  2. Once HD Voice has been enabled, follow these steps to activate Wi-Fi Calling.
    1. Go to the Home Screen.
    2. Open your Apps menu.
    3. Tap Settings.
    4. Look under 'Wireless & networks' section.
    5. Tap 'more...'
    6. Tap Wi-Fi Calling.
    7. Turn on Wi-Fi calling
    8. Follow onscreen instructions to enter a US address for use in the event of an emergency call (911).
      1. When setting up the location for the emergency 911 settings, please enter the address for the location you are most likely to be while using the Wi-Fi calling feature.