From my experience with third-party Facebook apps, I'm wary of adding apps from the Google Apps Marketplace to my Google Apps installation.
Can I trust apps from the from Google Apps Marketplace? Does Google vouch for them or review them in any way? Or should I only trust companies that I already trust?
Best Answer
As a developer of one of these apps (DokDok.com) I'd say commparing Google Apps Marketplace to Facebook apps isn't really fair. Data access is needed in order to provide real value to your existing Google Apps. The objective isn't to spread as fast as possible among your friend list for some sketchy reason.
That being said, I don't believe there's any official audit from Google so people with bad intentions could probably get their way for some time until the word gets out. An important point to keep in mind is that Google Apps APIs are accessed through OAuth (even email data). This means that as a 3rd party app, all queries on your data are made using a unique secret token that doesn't require knowledge of your password and, most importantly, can be traced back to my app.
If you're hesitant on a given application, read their privacy policy and terms of services which should explain what they do with the access you grant them. Also, don't hesitate to email the developer for more information. Some of our users did ask for precision and we were happy to explain in greater details what data we were accessing, when we were accessing it and our caching policies on that data.