H5打开APP

 let iosDownload = '******',  // 如果打开scheme失效的app下载地址
          andDownload = '*****';
      let u = navigator.userAgent;
      let isAndroid = u.indexOf('Android') > -1 || u.indexOf('Linux') > -1; //g
      let isIOS = !!u.match(/\(i[^;]+;( U;)? CPU.+Mac OS X/); //ios终端
      // 需要打开的app scheme 地址
      window.location.href = isAndroid ? '****' : '****';  // 尝试打开 scheme

      // 设置3秒的定时下载任务，3秒之后下载app
      setTimeout(function () {
        let hidden = window.document.hidden || window.document.mozHidden || window.document.msHidden || window.document.webkitHidden;
        if (typeof hidden !== "undefined" && hidden === true) {
          return;
        }
        if (isAndroid) {
          window.location.href = andDownload;
        }
        if (isIOS) {
          window.location.href = iosDownload;
        }
      }, 3000);