Wclock is described as 'Free, customisable, always-on-top world time clock for Windows computers'. There are more than 25 alternatives to Wclock for a variety of platforms, including iPhone, Windows, iPad, Online / Web-based and Android. The best alternative is World Time Buddy, which is free. Other great apps like Wclock are Time.is (Freemium), FoxClocks (Free, Open Source), Every Time Zone (Free) and Sharp World Clock (Paid).
FoxClocks is a Firefox/Thunderbird extension to display local times around the world in your status bar or any toolbar. Virtually all the worlds time zones are supported. FoxClocks also allows you to explore each time zone in Google Earth.
WorldClock shows you the time in different places over the world. Also included are the Swatch Internet Time, Julian Date and StarDate. You can also use it to synchronize the time with an atomic clock.