GNotifier

GNotifier integrates Abrowser's notifications with the native
notification system from GNU/Linux desktop. It supports: GNOME, KDE, Xfce,
Cinnamon, MATE, LXDE and Unity.

Everytime when Abrowser is finished downloading, it opens up the ‘Downloads Complete’ pop-up window. GNotifier replaces these window with the native notification, depending on your GNU/Linux distribution.

GNotifier entirely relies on libnotify library, so if libnotify is not present in your system, it will not work.