I tried to buy an activation code after the 15 trial was over, but couldn't find where to do it on the ArcSoft website.
No, the application isn't supported by the ArcSoft developers anymore. You might find it as a 3rd arty app (known as bloatware) on some old laptops that still have support for, but that's it. I've looked through all the available websites, but the software didn't appear to be available anymore.
You can check for the newest ArcSoft products using the following link: http://www.arcsoft.com/product/consumer/apps/