因为需要gmail帐户和密码，所以有风险，保险的方式是新建立一个匿名的 gmail 帐户。
方便的是：[TOOL] Real APK Leecher v1.3.5 – Always get your apk up-to-date easily
http://forum.xda-developers.com/showthread.php?t=1563894
For your own security and anonymity, if you doubt in giving your info to my tool, do not use your real google account in this app. Create a new anonymous google account, download 1 free app from google play to enable this anonymous play account, and then use this new anonymous google play account inside this app. If your account is like "nothing to loose", it’s ok
另一种是chrome 的插件，官网：http://codekiem.com/2012/02/24/apk-downloader/