How this iphone app got installed without me putting the password to download the app?

So I went to the App Store to download a editing app and when I went to my home screen the app was already downloading without asking me the password of my id so it can be download… Do you think someone did it?

Its because you already downloaded a diff app before, and didn't stop the program from running so it didn't require a password.

Did you download an app in the last 15 minutes within downloading that app? If so, that's why it wouldn't of asked for your password.

Other than that, I'm not sure then. Sorry