A third-party application is a product that’s not part of the main service that you’re using, but that has access to your main account or its credentials. For apps that you aren’t using regularly, consider revoking access to third-party application permissions from Twitter, Facebook and your phone.
For example, Hootsuite is a third-party application that works with Twitter. When you link up a third-party app with your Twitter account, you will see a screen asking for permission for the app to use your account. The third-party service will detail what the application will and won’t be able to do. Typically, apps can see your email address, read your Tweets, see who you follow, follow new people, update your profile, and even post Tweets. Most of these apps don’t actually do all of these things, but some third-party applications don’t have security standards as high as the ones the ‘mother’ service uses.
Check out Twitter’s explanation of which apps you may want to give your username and password to and which ones you might not want to trust with that information. Then revoke access for any unnecessary apps in the Applications tab of your settings page. Facebook has that information as well. (Be aware that revoking third-party app permissions may mean you’ll need to manually log into certain apps if you want to use them on your phone.)
Yael Grauer is a freelance tech journalist covering online privacy and surveillance for WIRED, Forbes, Slate, and other publications. Find her at http://yaelwrites.com or on Twitter @yaelwrites, and check out her free ebook on staying safer online at https://yaelwrites.com/saferonline.pdf.