One of the biggest reasons why many app developers continue to snub Android is piracy. The platform’s “open” approach, which allows applications to be downloaded from third-party sources and installed manually, makes it incredibly easy for users to circumvent Google Play and obtain paid apps completely free.

Piracy on Android is so rampant right now that just 5 percent of installs of Monument Valley — one of the best mobile games of 2014, which is currently priced at $3.99 in the Play Store — have actually been paid for.

Developer Ustwo notes that a small portion of the other 95 percent are legitimate downloads, too, but the vast majority of them were pirated. In simple terms, that means that if 100,000 people installed the app, Ustwo will have seen less than $20,000 in revenue after Google took its share… out of a possible $400,000.

That’s quite a difference. And to add insult to injury, Ustwo recently had to deal with a backlash from players who bombarded the game with 1-star ratings and bad reviews when it asked for a small fee to get its latest level pack.

“We’re not complaining at all by the way, it’s to be expected,” Ustwo said on Twitter. “It’s just interesting data.”

The piracy situation isn’t much better on iOS, either. While Apple’s tighter restrictions mean the vast majority of users cannot sideload apps themselves, those who jailbreak can. Only 40 percent of Monument Valley installs on iPhones and iPads have been paid for.

It’s not all bad news for Ustwo, of course. They have still created an incredibly popular game, which was recently chosen as one of Apple’s best iOS games of 2014 and has sold more than 1.4 million copies since its initial release back in April.

If you haven’t already played Monument Valley, I highly recommend it. But please, don’t download it without paying for it.

• SourceUstwo