NetSpeed for GNOME 3.8
GNOME Shell Extension
https://extensions.gnome.org/extension/104/netspeed/

Installation
Download ZIP
Extract NetSpeed-master.zip to ~/.local/share/gnome-shell/extensions/
Rename directory NetSpeed-master to netspeed@zpydr
Restart GNOME Shell Alt-F2 + r
Activate Netspeed in GNOME Tweak Tool