Billionaire is a new iOS game that challenges gamers to become the eventual richest person in the world. It even has lists of both real life billionaires and fantastical fake ones (such as Smaug) for you to compare yourself to, and to eventually beat. You can buy a load of businesses and use them to get filthy rich, possibly becoming the first trillionaire in the game.
"Nutaku (the world’s largest adult gaming platform) and the lewd game developer EXNOA, are today very excited and pleased to announce that the 18+ erotic city-building RPG “Billionaire” is now available via Nutaku for PC (via browser) and Android devices." - Jonas Ek, TGG.
Billionaire. is a business management clicker on the iOS and Android that's been out for quite awhile and is still extremely popular. There are two secret or semi-secret locations that you can buy much, much later on in the game, but they are covered in question marks early on. Even when you find out the names (Asgard and Pandora), they remain locked, but there are ways to unlock them.
Billionaire is a psuedo city-building game with graphics and a mechanic that pay homage to the old Make It Rain games that were wildly popular back in May or so on the iPhone and iPad. Your goal in this game is to make money and make money. That's it. Aside from money though, you also have premium currency in the form of crystals.