Android’s openness is something of a double-edged sword. On the one hand, it allows just about anybody to (relatively) easily write and publish mobile apps through the Play Store. But it also allows anybody to write and publish apps through the play store. And the checks to get apps approved aren’t quite as stringent as those found in Apple’s App Store.
But Google is doing something about it. They’ve just pulled 29 camera and photo apps from the Play Store after they were reportedly pushing intrusive ads, promoting porn, scamming users via phishing and even stealing content. But these apps have already been downloaded millions of times.