Security is one of the hottest topics going these days and Google is quite serious about it. Google even has a dedicated page for account management and security, allowing you to check out what data Google has on you, what devices are accessing your account, and, of course, stop any suspicious activity. Google has also had two-factor authentication in some form as an option for some time now. Users could approve sign-ins through the phone, a text message, an email and a few other options. The newest on that list rolls out today and it's actually quite simple; a prompt.
When a Google account with an active Android device or an active iOS device with the Google app is logged into from any device in any location, the account holder now has the option to see a prompt telling them what device is trying to access their account and its approximate location, represented as city and state or the rough equivalent, such as borough and village, county and township or prefecture and ward. If a prompt pops up that a user does not remember initiating, they can simply deny the sign in. Doing so will boot the other device and allow the user to take security measures to prevent future sign-in attempts. If the prompt is telling the user about a login that the user has sanctioned, they can simply allow it and that will be the last they hear of it.
Prompts are currently not enabled by default and must be activated on top of two-factor security. Once activated, users will be able to see the prompt and act on it as described above with no additional setup. In order to active the option, users can go to their security settings in their Google My Account page, then, under "Signing Into Google", go into the 2-step verification menu. The option will be there, requiring a simple click to turn on. The service comes with a few small caveats, of course; for one, Security Keys and Google Prompt won't play nice with each other. Only one can be enabled at a time. You'll also need a data connection. Android users will have to update their Google Play Services, since the Prompt is baked in. iOS users, on the other hand, will need the latest Google app.