World of Warcraft can be a bit calculator heavy if you want to play the game and make some money on the auction house.
It is a website and a mobile app which you can install on your phone. Feel free to use it as often as you like.
You can find the app right here.
Cost: Totally free of charge but your support would be greatly appreciated.
Here you can find some manuals you can use to install the apps on your device: