World Time Buddy - Effortless time conversion and world time.
Soulver - Soulver is a software application that functions as a calculator that allows you type a continuous stream of information rather than having to input data into multiple cells.
Time.is - exact time in any location
Numi App - Numi is a beautiful text calculator for Mac.
timeanddate.com - Free Clock for your website or blog!
Calca - Calca is an advanced symbolic calculator for iOS, OS X, and Windows that's as easy to use as a text editor.