You will need:
If downloaded from the internet add
Author (Date) Title of Program (Version) [Computer program]. availability. URL, (Downloaded: date)
TechSmith Corporation (2012) Camtasia Studio (Version 3) [Computer program]. Available at http://www.techsmith.com/download.html (Accessed: 21 June 2015).
In text citation
Camtasia Studio (TechSmith, 2012) can be used to...