$ sudo apt-get update
$ sudo apt-get install libindicator-tools 

libindicator-tools is installed in your system.

Make ensure the libindicator-tools package were installed using the commands given below,

$ sudo dpkg-query -l | grep libindicator-tools *

You will get with libindicator-tools package name, version, architecture and description in a table

libindicator-tools package basic information: