Install gtg by entering the following commands in the terminal:
sudo apt update sudo apt install gtg
Description:
organizer for the GNOME desktop environment
Getting Things GNOME! is an organizer for the GNOME desktop environment. GTG focuses on usability and ease of use. Its main objective is to provide a simple and yet flexible organization tool for life and work.
Homepage: http://gtgnome.net/
Version: 0.3.1-4
Section: universe/gnome