app that reminds to take a break at times

I am looking out for an app (for Mac OS X) that reminds to take a break (gives out a message) at pre-scheduled time.

Free (or low cost) app will do, as I don't want to spend my hard earned cash on this simple app.


An application that I use to be aware of the time on the computer is awareness it don't put a message only a sound indicating the time you have been using the computer without a break.


There is one such tool I know, called (unsurprisingly) Time Out. It's free as in beer and seems to be well-maintained.