FleevioChime
Chime on an interval or the clock
Play a gentle chime to stay aware of passing time — either on a rolling interval, or aligned to round clock times.
About Chime
Stay aware of passing time with a gentle chime — either on a rolling interval (every N minutes) or aligned to round wall-clock times such as :00 and :30. The chime keeps going as you browse and can send an optional desktop notification.