World of Warplanes is a game made by Wargaming.net the same developers behind World of Tanks, a very successful game where you control tanks and fight in a battlefield. The gameplay is a lot similar in their new game, just here you are a pilot of a plane.
Developers don't charge you for the game, but there is premium membership, you can buy gifts for your friends or buy in game gold, the currency which you can use to buy planes and other stuff which is important during the fights.
As for hacks or cheats for this game, there are few private hacks for which you have to pay lots of money. We tried one of the free ones from http://www.worldofwarplaneshack.com and I can really say that as for a free product it's really good.
This cheat tool provides you with a premium membership codes database, where you can find information which you can use to become a premium member of the game for free. It's not against the rules so you don't need worry about anything.
Also there is a gold hack with which I only was able to make 50000 gold and then it got bugged, but still I was able to use that gold. Contacted the guys who made to fix the bug.
All in all, it's good tool and also it's free, so it makes it perfect. If you want to download it, go to:
http://www.worldofwarplaneshack.com