To unpublish an app you first duplicate it. Next you delete the published version. You can then modify the duplicate and publish it when you've finished modifying it. Or you can leave it as unpublished.
Thanks Gysbert and Sangram for the info. Have one more doubt.Is there any way that i can display count of uniq data in a column.I mean out of all the data in that column i want to display only count of one specific data.Is there any expression in Qlik sense that can handle this kind of scenarios?