If users have access to create a new sheet in a published app (by duplicating) and then they can publish their own sheet to other users.
Once this is published,the app will show that as three separate lists
"Base Sheets" - which are the sheets create and published at the first
"Published by <user name>" - which are published by that particular user from his duplicated base sheets
(This list will grow to N number based on the users have access to that app, when each of the users publish from their own modified copy of base sheets)
"My sheets" - which are duplicated sheets of the base sheets ( when ever user tried to modify any base sheet or published sheet by another user it will create a duplicate sheet in My Sheets)
you have to implement security rules ( https://help.qlik.com/en-US/sense/3.0/Subsystems/ManagementConsole/Content/security-rules-overview.htm ) to prevent this behavior, so all the users who have access to the app will be able to create their new copy sheets and work on that but without publishing them.
Then Admin users can view those sheets in the QMC and they can move this sheet by changing the owner to their name and verify the newly created sheets and then approve it by publishing under their name. so we will have much better control, so at any point of time you will have base sheets, Sheets published by admin and MySheets.
Hope this helps you.
Have a look at Qlik Sense QMC Utilitiesif helps
The Sheet Approver enables users to approve published sheets in an app, thus, making them base sheets of the Qlik Sense application. In addition, it's possible to un-approve sheets as well and push them back to the community.