VirusTotal Uploader for OS X is a simple tool which scans a file, folder or application for malware with 50+ antivirus engines.
Using VirusTotal Uploader for OS X can be as easy as dragging and dropping a file onto the program window. You get to watch as it's uploaded, there's a delay while the site checks your file with all the main antivirus engines, and finally a "Detections" figure gives you the results ("0/53", hopefully), as well as a web link to the full report.
You can alternatively drag and drop an application onto the program, or an entire folder. But keep in mind that, even though VirusTotal Uploader for OS X is an "official" tool, it's still built using the site's public API. That imposes various limitations, such as only being able to run four queries a minute, so this isn't a suitable tool to scan your whole computer.
Whatever you're doing, a "Log" option displays the low-level details. This seems mostly aimed at developers, but if you're experiencing any program oddities then there may be some clues here (we saw a few "error fetching report" messages, for instance).
Yes, Macs can get viruses, too, but VirusTotal Uploader for OS X provides an easy way to check individual files against all the main antivirus engines.