Large Time CountDown Display.

I have an iPhone 4G. I work in TV industry where at times as a stage manager I need to count down host out of segment or into segment. The few backtime apps that I have seen have a very small time display. I need something with larger font display. If i knew how to program an iPhone I would make my own app - i have a book that I'm reading with the end of creating my own app.

Anyone know of an app that has a large screen font display that countdown?