PTHClock is an efficient menu bar clock software for Mac OS X that uses minimal CPU time and memory. It hides itself from the dock after starting, freeing up screen space.
One great feature included with version 1.1 is that the program will automatically hide itself from the dock after launching, which really helps to save valuable screen space.
Overall, if you're looking for a simple clock program to keep track of time while you work on your device, PTHClock is definitely worth checking out. Just keep in mind that it doesn't offer any other features or options beyond basic time display.
Version 2.3.2: N/A