Microsoft offers its Authenticator app for Android and iOS as a way of securing access to Microsoft and Azure accounts using multi-factor authentication. However, the functionality of the app is being expanded so it can also act as a general-purpose password manager and autofill solution.
As Thurrott reports, Microsoft made the announcement regarding the expanded functionality of Authenticator via its Tech Community website. Rajat Luthra, a program manager in Microsoft's Identity team explained, "I’m excited to share that Microsoft Authenticator can now securely store and autofill passwords on apps and sites you visit on your mobile device. Once you make Authenticator an autofill provider, it will offer to save your passwords when you enter them on a site or app’s login page."
Microsoft wants Authenticator to act as the only app you need for security on a mobile device, with all your logins protected and synced using a Microsoft account, be that outlook.com, hotmail.com, live.com etc. You therefore need a Microsoft account for this to work. If you are also an Edge user, the stored passwords will automatically sync with the browser on desktop. If you use Chrome, there's an Autofill extension to ensure syncing works for you.
For now, the new features are only available as part of a public preview. Trying it out requires updating to the latest version of the Authenticator app on your device and then navigating to Settings > Beta > Autofill where it can be enabled. You'll know it's turned on as a new Passwords tab will appear in the main app view. In order to make it the default autofill provider, open Settings on either iOS or Android and find the Autofill options. You can then select Microsoft as the default option.