https://qooah.com/2011/05/20/lg-%e7%a5%9e%e7%a7%98-android-%e6%89%8b%e6%a9%9f%e5%b0%87%e6%98%af%e8%b6%85%e9%ab%98%e8%a7%a3%e6%9e%90%e5%ba%a6/