The ability to set up notifications and an approval process on Google Forms. We use it as an Human Resources change form. A manager requests a salary change, a bonus request, department change, supervisor change, for example and it routes through the appropriate approval process (supervisors and CEO) and then a final copy to HR and accounting or whoever else may need it.

Ability to completely integrate submissions that require an approver or approvers without having to go outside of the app to secure documentation.

I like how smoothly this went but I ran into some interface issues that were frustrating. I would use it again but customer service is lacking.