Hi again!
You probably know this already, and perhaps you're already taking steps to improve it, but I can see that WindowBlinds makes some of its calls across the internet using HTTP, not HTTPS. In this example, it's checking for updates. I haven't done a full check of the network traffic, but I'd hope the registration and trial pages don't do the same thing. Since most of this website is HTTPS now, it would be surprising.
In addition, the installers for new versions of WindowBlinds come from http://storage.stardock.com which is also insecure. However, interestingly, storage.stardock.com does work over HTTPS if you ask it to, so perhaps consider setting up permanent redirects and HSTS pinning on your site to keep everyone safe. As someone who's dabbled in IIS before, I know this is really easy to configure.
