Password protection, in case someone picks up my phone
I don't want others to know what I am downloading. So password protect it before opening, even if it is running in the background. Then I don't have to worry if someone picks up my phone.
There are other apps that will provide this functionality because you would also need to lock down all file managers. Dont forget to disable notification for the app aswell.
The best and easiest option would just be to add security (passcode/pattern/face recognition/fingerprint) to your lockscreen.