This is the same app as available on the Chrome Web Store, but with one major difference: It does not ask for the "tabs" permission. Why is this important, you ask?
Its important because "tabs" seems to be the one privilege the app doesn't need. And the tabs permission results in the scary prompt asking "Access your tabs and browsing activity".
For more details, you can see my work on Privilege Abuse, and the online tool I made to counter against it.