WineBottler for Mac
is a tool that allows you to download and use Windows apps on your Mac. The accessible Windows applications include games, media player, and more.
WineBottler is not an emulator, with the programs, instead, running directly from your Mac. To open a Windows program on your Mac, find the file in .exe or .msi format. Then, drag it into WineBottler and convert it to an application that can be used as normal on your Mac.
It's easy to get started and free to use. Previous versions exist for iOS versions Tiger and Leopard.