I use Timebar, which is unfortunately no longer available through the Mac App Store. http://lifehacker.com/timebar-turns-your-macs-menubar-into-a-timer-48472431

I use Timebar, which is unfortunately no longer available through the Mac App Store. http://lifehacker.com/timebar-turns-your-macs-menubar-into-a-timer-484724310 http://lifehacker.com/timebar-turns-your-macs-menubar-into-a... It turns your entire top menu bar into a countdown bar which you can keep an eye on peripherally as you work.