RealBigClock

This app is intended for use by swimmers, runners, cooks, the visually impaired and anyone else who wants a simple but SILENT, purely VISUAL clock or timer. The numbers are LARGE to be readable from a distance of 10-20 meters.
The clock will alternate every second between displaying hours and minutes.
The constant alternation makes it easy to make out the time.
The most commonly used timer durations can be selected from a drop down list.
The display changes VISUALLY from BLACK & WHITE to RED when the timer expires.
The app reacts to the current light levels in the area and will show black on white in bright light and white on black in darkness.