I am monitoring a competition where each sprint is scheduled to one hour interval. Each team member should have a count down c'lock on the screen, preferrably on terminal. The c'locks should lauch alarm after 45 minutes, 55 minutes and and 60 minutes. 

The enviroment should create a feeling of extreme programming. Is there some ready terminal application for the job? 

**[Clarification]** The teams are using Ubuntus and Macs.