Users of newer versions of Windows or just about any Microsoft web service might be familiar with the company's rudimentary two-factor authentication system. If it's been a while since you've logged in or you're setting up a new Windows device, it might ask you for a verification code, accessible from a backup email account. Of course that can be a pain if you don't remember the password for that account, or simply don't want to dig it out. Now you don't have to.
The Microsoft account [sic] app allows you to use a two-factor authentication system without the usual email, text message, or call option. Once you've set it up and connected it to your Hotmail/Live/Microsoft account, alerts for two-factor logins will be sent to the app, and all you have to do is tap the icon to get access. No typing in codes, no listening to robo-calls. Nice.
Of course, if you've set up a Gmail address as the backup for your Microsoft account, you get the authenticator emails more or less instantly on your Android phone. If that's the case, this app is only really useful if you log in and out frequently, say, for a work desktop or your friend's Xbox. Microsoft notes that users of the Azure cloud system should use this existing app instead.