Well, a forerunner is a wristwatch that helps you to keep track of your training during and after the exercise. It monitors the pace, the heart rate, the speed, the route, etc.
How to configure it? (once)
Open a Terminal for the installation 
tar -xjf gant-master.tar.bz2
Forerunner 405 and the ANT usb are ready!
How to use it?
1. Plug the ANT usb into your computer and set your wristwatch in Pairing mode as shown below
Menu > Settings > ANT+Sport > Computer > Pairing > set to On
The wristwatch will ask you whether you want to pair it or not. Also check that,
Menu > Settings > ANT+Sport > Computer > Force send > set to Yes
Menu > Settings > ANT+Sport > Computer > Enabled > set to Yes
2. After that, two commands are required to connect devices and to download all data. 
/home/littleowl/gant-master/gant -f littleowl -a auth405 (accept pairing on your wristwatch)
/home/littleowl/gant-master/gant -nza auth405 > output
I added two icons to launch these commands from the Desktop (launchers), thus I don’t need to use the Terminal anymore (command-line interface) 
 Ubuntu 9.10 – Karmic Koala
 Replace littleowl with your username
 Commands for Desktop launchers:
– Icon 1: /home/littleowl/gant-master/gant -f littleowl -a auth405
– Icon 2: /home/littleowl/gant-master/gant -nza auth405
– Destination folder: /home/littleowl/*.TCX