Shadowsocks-Qt5 is a native and cross-platform shadowsocks GUI client with advanced features.

sudo add-apt-repository ppa:hzwhuang/ss-qt5#add repo for qt5， else ubuntu may not find the host
sudo apt-get update
sudo apt-get install shadowsocks-qt5

The excuted-application will be located in /usr/share/Shadowsocks-Qt5 path, under Ubuntu system, you can doubleclick it to open.
Add a new access, and config your ss servers.

sudo add-apt-repository ppa:hzwhuang/ss-qt5#add repo for qt5， else ubuntu may not find the host
sudo apt-get update
sudo apt-get install shadowsocks-qt5

下载后客户端在/usr/share/Shadowsocks-qt5, 双击打开后，创建一个新的连接，然后配置自己购买的ss服务器。