Do any game apps actually pay real money?

I've heard rumors that there are game apps out there that offer players the chance to earn real money. But is it really true? Can you tell me more about these apps? Are they legitimate, or are they just scams? What kind of games are they, and how do they work? Do you have any personal experience with these types of apps? I'm curious to know if it's actually possible to make a decent income playing games on my phone or tablet. Any insights you can provide would be greatly appreciated.