https://qooah.com/2013/02/27/ubuntu-touch-%e9%96%8b%e7%99%bc%e8%80%85%e9%a0%90%e8%a6%bd%e7%89%88%e6%94%af%e6%8f%b4%e5%b0%87%e9%81%94-20-%e6%ac%be%e8%a3%9d%e7%bd%ae-2/