Pro users have sessions that last 90 minutes. In addition, you can host your own server and run apps for an unlimited amount of time.
A pause button will never be implemented, because it would not make sense for the Cameyo Team. The servers are already overcapacity. Adding a pause button just means a bunch of free users will keep sessions they aren't actively using alive, which will prevent people who are actually trying to get work done from using the service. It just does not make sense. I hope this sheds some light for you.