The Verge: “…Authentication apps generate one-time numerical passcodes that change approximately every minute. When you log in to your service or app, it will ask for your authenticator code; you just open up the app to find the randomly generated code required to get past security. Popular options include Authy, Google Authenticator, and Microsoft Authenticator. These apps mostly follow the same procedure when you’re adding a new account: you scan a QR code associated with your account, and it is saved in the app. The next time you log in to your service or app, it will ask for a numerical code; just open up the authenticator app to find the randomly generated code required to get past security. Here is how to set up 2FA on some of the more popular online accounts. Not all of them allow for authenticator apps; in that case, we list what is available. (If you’re just interested in using an authenticator app for your Twitter account, you can go directly to this article, which gives you all the steps needed — however, just to be convenient, we’ve included Twitter with the others here.) Note: most of the following directions are for websites; if you can use a mobile app, directions will be given for that as well…”