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