Google Drive lets users install an app by approving an OAuth 2.0 access
request. To prompt users for installation, apps can request the scope
https://www.googleapis.com/auth/drive.install. Users see a dialog like this:
See Authorizing Your App with Google Drive for more information about scopes you can request for Drive apps, and how to request them.
Next steps
An installed app needs to be able to handle create and open actions launched from the Drive UI. See Create Files or Open Files to learn more.