$ sudo apt-get update
$ sudo apt-get install gnome-shell-pomodoro-data 

gnome-shell-pomodoro-data is installed in your system.

Make ensure the gnome-shell-pomodoro-data package were installed using the commands given below,

$ sudo dpkg-query -l | grep gnome-shell-pomodoro-data *

You will get with gnome-shell-pomodoro-data package name, version, architecture and description in a table

gnome-shell-pomodoro-data package basic information: