Followup from previous comments. It looks like the site is active again. Based on the website and previous emails with the company, no upgrade paths are available for previous purchasers. Instead you must buy it again at full price. Only support available is via email and the infomation in the FAQ is quite limited. Additionally their privacy policy is a link to Google rather than their own. No information is provide about the developer or company on their website. License only covers upgrades till 5.9..9 leaving the impression that if or when they come out with version 6 you will likely need to completely purchase it again. Finally, when the product became incompatible with current MacOS updates, it literally took years for them to upgrade the product. There is no indication currently that it works with MOS 10.15. Will MOS 10.16 break it again when released? Will it once again take years to update? Right now, based on the information on MacUpdate and the developers website it is anyones guess.
As is quite obvious to this review I am not a big fan of the 'Mushroom Treatment' - i.e keeping customers in the dark and feeding them manure.