Hi @Anonymous ,
I'm afraid it's not supported to hide or close an app in powerapps currently.
Here are two alternative ways for your reference:
1)Firstly, export this app. Then delete this app. When you want to use it, import this app.



2)make all other people do not have permission to this app.
Firstly, delete all the users except owner in the share manage page.

Then, ask your talent global admin assign all the users except you with the security role that can not read/write this app.
Or you could also create a new environment, import this app in the new environment. Make others all could not read and write this new environment. Delete this app in the original environment.
Best regards,