It would be great if there were another sharing option besides User and Co-Owner. I'd love to be able to give people read-only access to an app in the Powerapps Studio. Like an "Auditor" level, for example. This would be very useful for code reviews and training.
As adoption increases and the base of citizen developers gets larger, I get more and more requests for copies of my apps for others to examine and learn from. Making safe copies that aren't connected to real, live data sources isn't that easy. It's pretty cumbersome, in fact. It would be nice if people could open an app in the studio, see how the sausage is made, but not be able to change anything.
I work mainly with canvas apps but perhaps this could apply to model-driven as well. I wasn't sure where to put this comment, so if there's a better thread, please let me know.