WIP for Qlik Sense app are slow to check-out / check-in
If the application contains big media in In app the .qvf size will be huge even without data, so will slow up check-in and check-out processes.
Ensure you are not embedding huge medias, prefer to us Content Library Items (that you can manage with wip also)
Note : you can see the app media in the QMC / App / App Content