APT indicator applet
APT Indicator is a small applet that
looks like small icon on system tray of your window manager.
This applet will notify you about available new packages for your
system, e.g. security updates,
using APT software management system.
See help documentation for this applet here
Download latest version here
APT Indicator is written by is
written by Stanislav Ievlev and Sergey V Turchin