Kapow is a free and open source punch clock application for Linux and Windows. Using this application you can Keep track of time spent on projects. It is released under the GNU General Public License v3.0. You can start clock by using Start/Stop button and also edit any of the entries. If you charge or bill project per hour basis then this is good app for you.
Install Kapow Punch Clock on Ubuntu Linux
Kapow Punch Clock is available via flatpak and Ubuntu PPA. Install flatpak and flathub on your system and restart it after the installation. Now open the terminal application (ctrl+alt+t) and run below Kapow Punch Clock flatpak installation command to install it.
flatpak install flathub org.gottcode.Kapow
After the installation open Kapow Punch Clock using
flatpak run org.gottcode.Kapow
And you can also uninstall it via
sudo flatpak uninstall org.gottcode.Kapow
Install Kapow Punch Clock via PPA:
In your terminal app run below commands one by one.
sudo add-apt-repository ppa:gottcode/gcppa
sudo apt update
sudo apt install kapow