微信APP下载页面window.var u = navigator.userAgent, app = navigator

<!doctype html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="Generator" content="EditPlus?">
    <meta name="Author" content="">
    <meta name="Keywords" content="">
    <meta name="Description" content="">
    <title>智能韶力APP下载</title>
</head>

<script type="text/javascript">

    window.onload = function() {
        /*智能机浏览器版本信息:*/
        var browser = {
            versions: function() {
                var u = navigator.userAgent, app = navigator.appVersion;
                return {//移动终端浏览器版本信息 
                    trident: u.indexOf('Trident') > -1, //IE内核
                    presto: u.indexOf('Presto') > -1, //opera内核
                    webKit: u.indexOf('AppleWebKit') > -1, //苹果、谷歌内核
                    gecko: u.indexOf('Gecko') > -1 && u.indexOf('KHTML') == -1, //火狐内核
                    mobile: !!u.match(/AppleWebKit.*Mobile.*/) || !!u.match(/AppleWebKit/), //是否为移动终端
                    ios: !!u.match(/\(i[^;]+;( U;)? CPU.+Mac OS X/), //ios终端
                    android: u.indexOf('Android') > -1 || u.indexOf('Linux') > -1, //android终端或者uc浏览器
                    iPhone: u.indexOf('iPhone') > -1 || u.indexOf('Mac') > -1, //是否为iPhone或者QQHD浏览器
                    iPad: u.indexOf('iPad') > -1, //是否iPad
                    webApp: u.indexOf('Safari') == -1 //是否web应该程序，没有头部与底部
                };


            } (),
            language: (navigator.browserLanguage || navigator.language).toLowerCase()
        };


        if (!isWeiXin()) {//非微信
            if (browser.versions.ios || browser.versions.iPhone || browser.versions.iPad) {
                //苹果app下载
                location.href = "https://itunes.apple.com/cn/genre/ios/id36?mt=8";
            } else if (browser.versions.android) {
                //安卓app下载
                location.href = "http://download.com/shaoli.apk";
            }
            else {
                //PC下载
                location.href = "http://download.com/shaoli.apk";
            }
        } else {//微信
            document.getElementById("img").style.display = "block";
        }
    }

    // 判断是微信
    function isWeiXin() {
        var ua = window.navigator.userAgent.toLowerCase();
        if (ua.match(/MicroMessenger/i) == 'micromessenger') {
            return true;
        } else {
            return false;
        }
    }
</script>

<body style='padding:0px;margin:0px;'>  
<img id='img' src="img.png" width="100%" height="100%" style="display: none;"/> 
</body>
</html>