There are a lot of Internet applications that use your Twitter account to authenticate specific activities. From the main Twitter screen, click on your profile icon in the top right, then click “Settings” from the drop-down. On the left side of the next screen, click on the “Apps” option to see how messy it can be when you forget how many different applications have access to your Twitter account. For each application, click the “Revoke Access” button. It’s a good idea to clean this out frequently to make sure that third-party apps don’t have permissions that you don’t want them to have.