Redshift Plasmoid is a full featured KDE interface to the Redshift daemon, which allows the user to change the color temperature of the screen according to the surrounding light, which is meant to protect your eyes from the bright light of the screen.
Activity Manager manages the KDE Plasma desktop activities effectively. It allows start, stop, add, edit and remove activities and switch between them either graphically or by scrolling the mouse wheel over the widget.
Timekpr allows the user to limit the daily computer usage based on the allowed login time window and on login duration period. The application can be used as parental time control to limit child access time.