1. Open the AppStore on your device.
  2. Tap the Updates icon on the bottom panel.
  3. If a new update is available for your game, it will appear on the list. Tap Update next to the update description to download it.
You can also adjust your device settings to automatically download updates for the apps you have installed:
  1. Go to Settings -> iTunes and App Store.
  2. In the Automatic downloads section, turn Updates on.