Types of Google Apps Deployment (and billing users)

[Milan Čapoun]

Hello,
what are the types of Google Apps Deployments?

Google App Engine Apps
So far I thought there is just one type - the one developed using Google App Engine. Suich application would be deployed "inside" the customer's Google App Account (Meaning he would Add it from marketplace and the application would run in his account cloud environment)
Billing would be according to machine time, traffic load etc... the same way as native Google Apps are (Word, Excel, ...)

"Standalone" Apps
I have tried some Google Apps playing the role of customer and my experience is different.
I (as a customer) have installed these apps from my Google App Account.
but when I use these applications it redirects me to the site of the provider and it seems the only integration with Google is SSO (no need to login).
But the application itself runs on the vendor's environment (say his Amazon EC2 env but NOT Google)
Example of such application is surveymonkey (https://www.surveymonkey.com/home/)
The pricing is based on number of questions then. (nothing to do with Google machine time consumed, ...)


So far I haven't found any app runing inside the Google App Account cloud - everything I have tried was this "standalone" app with SSO.


Is this the most common way how the Google Apps on the marketplace are distributed?

Thanks very much for any hint.