More than likely, that app is used to either launder funds or get money out of stolen credit cards.
Doesn't matter if the cash has already been funneled overseas. Good luck extraditing someone on credit card fraud from Cambodia.
Apple iCloud fraud team doesn't communicate sufficiently or at all with Apple App Store fraud team, because the losses are seen as chump change or due to organizational friction. App gains traction in App Store due to high revenues and low complaints.
Eventually someone not-tech-savvy will download it and complain. Then, maybe, it will get taken down. Or if someone writes a popular blog post about it.
And even before these apps became "successful", they should have gone through some review process. Clearly they were not reviewed at all.