Appstore gives people a false sense of security. They think everything available on apple platform is legitimate and thoroughly tested, but one thing I know about scammers/hackers, they always try to get a way around.
I'm curious how these kinds of apps in the App Store/Play Store can't be easily taken down and easily pass and allowed to be in app stores, as far as I know, before you can publish some apps in these app stores, there are some verifications needed.