kwin-addons software package provides additional desktop and window switchers for KWin, you can install in your Ubuntu 16.04 LTS (Xenial Xerus) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install kwin-addons
kwin-addons is installed in your system.
Make ensure the kwin-addons package were installed using the commands given below,
$ sudo dpkg-query -l | grep kwin-addons *
You will get with kwin-addons package name, version, architecture and description in a table
| Distro | Ubuntu 16 04 lts xenial xerus |
| Section | KDE |
| Package | kwin-addons |
| Version | 4:5.5.5-0ubuntu1 |
| Description | additional desktop and window switchers for KWin |
| Sub Section | KDE |