js判断移动端是否安装某款app的多种方法

<script language="javascript">
 if (navigator.userAgent.match(/(iPhone|iPod|iPad);?/i)) {
  var loadDateTime = new Date();
  window.setTimeout(function() {
   var timeOutDateTime = new Date();
   if (timeOutDateTime - loadDateTime < 5000) {
    window.location = "要跳转的页面URL";
   } else {
    window.close();
   }
  },
  25);
  window.location = " apps custom url schemes ";
 } else if (navigator.userAgent.match(/android/i)) {
  var state = null;
  try {
   state = window.open("apps custom url schemes ", '_blank');
  } catch(e) {}
  if (state) {
   window.close();
  } else {
   window.location = "要跳转的页面URL";
  }
 }
</script>

转自：

http://www.jb51.net/article/76585.htm