It is a commercial program that has versions for both Windows and Mac. Though a whole host of them exist, the emulator I tend to use is Bluestacks.
If your buddies are all on Kik, it’s the only viable option right now unless you want to be glued to your iPhone or iPad all day and night to stay in touch. It runs a little slow, as it isn’t a native app, but it does work. Ironically, even though there is a Kik app for iOS, the best way to get it on a Mac is to use an Android emulator that runs on Mac OS.