Taking a look under the hood
It is well known that your Facebook account has to give permission to apps before using any third party service, be it a game, photo sharing tool, or frictionless news viewing. These apps request permission to take action on your behalf (for example, Spotify users’ listening habits are automatically shared as status updates) or require permission to see your account information (like who you are friends with, your interests, etc.).
Many people are unaware that they may have given permission to Google to do the same thing, and while it is not necessarily a bad thing, it is something you should be aware of. The major problem is that most of the Google help pages point to old settings, and the new settings are in a far different place, so Google is not exactly helpful in this arena.
How to check your permissions
To find out what apps have permission to see your Gmail account and browsing habits associated with the Gmail account, whether it was done through Google+ games, Gmail authentication, Google accounts, or otherwise, simply log into your Gmail/Google account, click your profile picture (or name) on the top right in the black bar, and select “Account” which will take you to your Google Account Overview (or you can cheat and just click here).
Next, on the left sidebar, click “Security,” and then next to “Authorizing applications and sites,” click the grey “Edit” button. Most of us were surprised at how many third party apps had access to our Gmail accounts, even though we were the ones that granted permissions.
If something looks strange, or you do not recognize it, revoke access, but write it down or email yourself a list of what was revoked in case some of your Gmail features stop working – it can often feel like a third party feature is native to Gmail because you’re used to it, and you don’t want to get stuck without remembering what it was called.