- Notification area (AKA system tray)
- Application launcher
The FVWM-Crystal window manager adds exactly these features to vanilla FVWM, along with other subtle goodies all over.
Lack of desktop icons has never been a problem to me. Launchers are best left in a corner, so there is no need to "show desktop" or "hide windows" in order to use icons.
Another nice thing about FVWM-Crystal is the ability to start a terminal just by right-clicking anywhere on the desktop. Even blank areas between launcher, workarea switcher and notification area would do, so there is no need to resize a maximized window to do this. Another nice thing is the ability to start a small terminal by pressing Alt + grave(`).
I know several users who have switched to FWVM-Crystal and are happy. :-)