The Case Apps were (are) great, but they are pretty hard to get now:
One thing you might try is downloading this zip and running the Application Reference file. Turns out something is still alive out there…
at http://www.case-dev.com/revit/installer$/FreeAddInManager/CaseRevitAddInManager.application
Tick the Terms & Conditions box and then tick the boxes for the apps you want to install.
Note: we also had to disable Microsoft Security Essentials (Windows Defender Real-time Protection) to get this application reference to work.
Here is the big list of apps in the Apps Manager: