I recently used If So for a client project where we wanted to hide a section of the site (documentation) to all visitors except ones that are logged in to a 3rd party app. Using the Cookie condition, we were able to get the functionality we wanted. It wasn't easy as we had to integrate with Better Docs, WPML and also get it to work with WPEngine caching, but Josef helped me out through the whole process until we had a working solution.

I purchased 3 codes as I can see myself using the plugin for several other clients and the price is a steal compared to their 200$/year price.