in version 0.9 and 0.9.1 the tray icon does not appear.
reason for this is that the path to the icon is not palid .
so just change this line in starting of main.c
#define ICON_PATH "path to your icon"
and compile
in version 0.9.1 text "NetSend" appears in the tray if it's not able to find
icon. So update to latest version :)
Gaurav