У вашего броузера проблема в совместимости с HTML5
Shush is an App that allows you to set how long you would like to turn your ringer off and what level you want it to return to when the time is up.
Get it free here: https://market.android.com/details?id=com.publicobject.shush&feature=search_result#?t=W251bGwsMSwxLDEsImNvbS5wdWJsaWNvYmplY3Quc2h1c2giXQ..