Cathedral bells, grandfather clocks, digital watches: they all remind us of the passing of time by striking a bell or a chime. If you’re prone to becoming engrossed in your work (or play), a timely clock toll can help bring you back to Earth now and again.

Cuckoo brings hourly clock chimes to Mac OS X. Play a beep on the hour. Or on the half-hour, or any combination of five-minute intervals. Use one of Cuckoo’s built-in tones […] or any of your Mac’s installed sounds, at a custom volume. (Coo!)