Using Timekpr Revived, you can control the computer usage for certain user accounts by setting some predefined access rules. In recent weeks, Timekpr Revived has received support for KDE Plasma (the developer tested it in Kubuntu 18.04), as well as some important Ubuntu 18.04 (Gnome) fixes. As a result, Timekpr now runs in Unity, Gnome, KDE, Xfce, and MATE.