When you view the apps that you've given permission to, what they can do will be listed next to them. For some apps, it's necessary (like being able to add an event to your Google calendar), while others shouldn't be asking for anything more than your basic information (your name and email address for single sign-on purposes). Google allows developers to request three levels of information, basic, read and write, and full access. What happens when you revoke access to your Google account for third-party apps.How to revoke third-party app permissions for your Google account.Take a look at what apps you've given permission to and revoke access to ones you no longer use. Google has much stricter privacy policies about what third-party developers can do with your data, but it's still a good idea to clear out any apps or games you no longer use. Google helps app and game makers with a single sign-on service similar to Facebook.