Discover Championship Spades Pro
This program is not free, but there is a bannerware version available that you can try out for free before you decide if you want to buy or not. If you don’t want to limit yourself to playing just inside your own computer, setting up a local network is possible and you can also go to the online version. The online version has a player chat.
CardShark Spades
CardShark Spades is famous for the many features and settings. It works only with Windows. A free trial copy is available.
Hardwood Spades
Hardwood Spades has a fantasy theme and really nice graphics. You can play online or offline.
Infinite Spades
Infinite Spades lets you play against “robots”, i.e. not against real players. You decide if your opponents should be on the beginners level or at the experienced level.