1. Chrome

sudo wget http://www.linuxidc.com/files/repo/google-chrome.list -P /etc/apt/sources.list.d/
wget -q -O - https://dl.google.com/linux/linux_signing_key.pub  | sudo apt-key add -
sudo apt-get update
sudo apt-get install google-chrome-stable

2. JDK8

sudo add-apt-repository ppa:webupd8team/java
sudo apt-get update
sudo apt-get install oracle-java8-installer

3. Fcitx

sudo add-apt-repository ppa:fcitx-team/stable
sudo apt-get update
sudo apt-get install fcitx

4. Flash

open Software & Updates and on the tab "Other Software" make sure Canonical Partners is ticked

sudo apt update
sudo apt install adobe-flashplugin

5. ShadowSocks

sudo add-apt-repository ppa:max-c-lv/shadowsocks-libev
sudo apt-get update
sudo apt install shadowsocks-libev