POLO TIME FOR ANDROID IS AVAILABLE HERE.
Polo Time is a feature rich timer specifically designed for polo.
With Polo Time you can stop watching the clock, it sounds a beep 5 seconds before you need to ring the bell or blow the horn, and then it plays a horn for the 30 second warning and three horns for the end of a chukker. It rings a bell for chukker warnings and three bells at the end of a breaks and halftime.
Polo Time for IOS should be available later this year.