I bought the VibraLITE 3 Vibrating Watch for my 10 year old son. He needed to be reminded to use the bathroom and this watch did the job. He liked that it was discrete and quiet for school but preferred the audible alarm on weekends.
Discreet and Comfortable
My 9 year old wears the Vibro-Watch 12 Alarm Vibrating Watch 24/7. The vibration is discreet so no one knows that its function is to tell him when it is time to void his bladder. This watch protects my son from embarrassment.