First, confirm that you have a working Internet connection (if you are playing on Wi-Fi, double check that it hasn't stopped working). If you do, try this:
Double click the home button on your iDevice.
Find the Hanging With Friends icon in the bottom bar.
Tap and hold the icon and then tap the minus symbol on it to kill the app.
Single click the home button.
Open Hanging With Friends.
Open your Android device's Settings.
Tap on "Applications."
Tap on "Manage Applications."
Select "Hanging Free"
Push the "Force Stop" button.
Return to your home page and open Hanging With Friends.