It's been over five months since Microsoft Authenticator Beta showed up in the Windows Store. The app combines the two-factor authentication process for Microsoft, Azure Active Directory (AD), and more.
Essentially, it's a combination of the old Azure Authenticator and Authenticator apps that were available for the platform. Authenticator served the purpose of signing into personal Microsoft accounts, but it was a Windows Phone 8.1 app.
In August, the company launched Microsoft Authenticator for iOS and Android, promising that it would show up for Windows 10 Mobile later that week. After three months of broken promises, the full app is finally available in the Windows Store as an update to the Azure Authenticator app.
If you're using the old Authenticator app for Windows Phone 8.1, it's important to note that you'll need to download a new app. This shouldn't be surprising, as the iOS and Android apps also showed up as updates to the Azure Authenticator apps.
To download Microsoft Authenticator or update your Azure Authenticator app, click here.