Once an app reaches a certain level of popularity, you begin to see "knock-off" apps, which are apps with a curiously similar name and icon (and screenshots and description), but which in fact don't do anything except blast the user with full-screen ads at every turn. It's literally just ads; they don't perform any actual function; they just exploit the SEO boost to serve ads to unsuspecting users.
I have tried "reporting" these apps numerous times (there are dozens of them), but Google has done nothing at all to remove these apps or suspend the accounts of these bottom-feeding "developers". The only conclusion is that the ad revenue benefits Google as well as the bottom-feeders, so Google drags its feet in taking any action. I would bet that if these apps were doing something malicious without a financial incentive for Google, then Google would take them down in a heartbeat.