In GAT, under configuration select Alarms, we have a default setting to warn Admins when new third party Apps with data access scopes.
These alarms can be sent to a list of Admins or security officers. Some of these apps request extraordinary levels of access and should be investigated.
You can examine the Apps installed on your domain by selecting ‘Applications’ from the audit section of GAT.
When in the Applications audit you can filter by user, group or OU. You can also search by App name or URL. These apps can then be allowed or banned on an individual, group or OU basis. See how here. Banned apps will have the ban enforced automatically by GAT.
Sometimes you might prefer if the user made his or her own informed decision about removing apps s/he has granted access to. The problem is Google does not make it particularly easy for users to find this information.
If you installed third-party apps and forgot or were unable to remove them, then the following steps will show you how to review and remove these apps. By removing their access it just means they will have to request access again the next time you use them. In the meantime, if you revoke access, the apps will not have access to your data.
On the top right of your email page click on your image or avatar.
From the pop-up window select ‘Google Account’. A new tab will be open, from the left hand side select and open ‘Security’ tab. Scroll down a little and you will see ‘Third-party apps with account access’ simply select ‘Manage third-party access’.
A list with all ‘Apps with access to your account’ will be displayed. (See image on next page).
Under ‘Third-party apps with account access’ a list of apps with access to your Drive will be displayed. Clicking on each of them You will have an option to remove the access.
Some of these will be important and used every day.
Some will be tools you granted access to for a ‘one off’ tasks like editing a photo and are no longer required. Scroll down the list and for those tools, you are sure you no longer need, select the line they are listed on and then select ‘Remove access’.
In general, all tools produced by Google are going to be just fine to leave installed, even if you don’t know for sure what they are doing.