gxkb software package provides X11 keyboard indicator and switcher, 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 gxkb
gxkb is installed in your system.
Make ensure the gxkb package were installed using the commands given below,
$ sudo dpkg-query -l | grep gxkb *
You will get with gxkb package name, version, architecture and description in a table
| Distro | Ubuntu 16 04 lts xenial xerus |
| Section | X Window System software |
| Package | gxkb |
| Version | 0.7.6-1 |
| Description | X11 keyboard indicator and switcher |
| Sub Section | X295 |