检测手机上是否有某个应用，没有就跳到应用市场

public static final String APP_PACKAGE_NAME = "com.*.*";//包名
 
    /**
     * 启动薄荷App
     * @param context
     */
    public static void launchapp(Context context) {
        // 判断是否安装过App，否则去市场下载
        if (isAppInstalled(context, APP_PACKAGE_NAME)) {
            context.startActivity(context.getPackageManager().getLaunchIntentForPackage(APP_PACKAGE_NAME));
        } else {
            goToMarket(context, APP_PACKAGE_NAME);
        }
    }
 
    /**
     * 检测某个应用是否安装
     *
     * @param context
     * @param packageName
     * @return
     */
    public static boolean isAppInstalled(Context context, String packageName) {
        try {
            context.getPackageManager().getPackageInfo(packageName, 0);
            return true;
        } catch (NameNotFoundException e) {
            return false;
        }
    }
 
    /**
     * 去市场下载页面
     */
    public static void goToMarket(Context context, String packageName) {
        Uri uri = Uri.parse("market://details?id=" + packageName);
        Intent goToMarket = new Intent(Intent.ACTION_VIEW, uri);
        try {
            context.startActivity(goToMarket);
        } catch (ActivityNotFoundException e) {
        }
    }