HTTPSChecker 3.0 for Mac was available to download from the developer's website when we last checked. We cannot confirm if there is a free download of this app available.
Please check the Mac app with an antivirus before launch as it is downloaded from the developer's website, and we cannot ensure that it is safe. The software lies within Developer Tools, more precisely Webmaster Tools. This free Mac app was originally designed by Wildfire Internet. The file size of the latest downloadable installer is 54.3 MB.
From the developer:
HTTPS Checker is an application that allows you to check your website for common HTTPS migration issues. The program can find insecure HTTP content loaded over HTTPS, to keep data private, unmodified and trusted by visitors. The service is dedicated to helping site owners, designers and developers migrate from HTTP to HTTPS / SSL with ease.
You may want to check out more software for Mac, such as ModelBaker, iGooMap or PageRank Viewer, which might be related to HTTPSChecker.