Publisher: Blizzard Entertainment, Inc.
Platform: Windows Phone
Fortunately, the developer/publisher for some of the world's best MMOs, Blizzard, has given players the ability to add an authenticator to their account for years now. There has been an app available for Android and iOS for some time now. Windows Phone users are no stranger to apps taking some time to see life on this platform, but the wait is usually worth it. And until now, there have been the keychain authenticators which serve the same purpose.
The Windows Phone app does exactly what it needs to. It generates unique, one-time use codes that work in conjunction with the account. That way if someone tries to log into your account, they'll also be prompted for the authenticator code. Without it, there's no way for them to log in. It's a fantastic way of adding extra security to your account and a must have for any user of Blizzard's services.