I grew up on simulation games, along with all those games about killing people, so I know how to spot a good one. And Pocket Academy is a good one.
It's hard to believe, looking back on it, that Maxis never put together a school simulator. They made one about an ant colony, but not a school? Weird. Pocket Academy, though, is here to fill that void, and it's a true, complex simulation.
The goal here is to build a prep school that people want to come to, so you can make more money and build new facilities and attract more students. And so on and so forth. Pocket Academy isn't as open ended as, say, Sim City, though. It does have scenarios and goals for you to try to accomplish.
When I call it complex, I'm not being polite. Pocket Academy is one of those games that you have to read the very long "how to play" section, or else you just won't have any idea what's going on. From there, the game eases you into things by sort of guiding you through the process of improving your school in a bit of a tutorial, which you will appreciate or perish.
Yes, tutorials are evil, but in this case they're ultimately rewarding, because once you do them you can actually play the game. And the game is fun. So just suffer through the first bit, and you'll be on your way to an addicting good time.