This is a free windows program that assists in setting up the right geometry (servo arm length, rudder horn length and offsets) in order to make sure your pull-pull cables don't get tight when they are moved. It is licensed to run through July 2015.

Credits
Mr David McQuinn from Chesterfield Missouri USA (Explicit permission obtained from David, in fact Gentleman as he is, promised me to send future versions, for hosting it here too)

PS
File is larger than permitted, i have mailed it to Anwar Bhai to make it available below for download