An application update occurs to correct any bugs in the current version or to add improvements to the game. Updates are important and can sometimes allow you to unblock any problems with your game.
For an Apple device (iPhone, iPad ou iPod), you can visit the App Store, select Updates
on the bottom of your screen (a red number with indicate how many updates are available for your device).
A list of updates will be shown. Click on the desired application update or you can choose "Update All".
For an Android device, you can visit the Play Store, click the icon in the top left corner, then choose My Applications
, and then Update
In both cases, you must have internet connection to update your device.