What I'm working on is different but similarly aimed at breaking through the intermediate plateau. I'm generating comprehensible input in podcast form, targeting the vocabulary used to fit a specific learning goal (e.g. "I want to be able to watch show X without subtitles") and systematically repeating the words at specific intervals to improve retention.
It works well as a prototype. I've listened to it for ~16 hours so far and it does seem to help me with vocabulary acquisition.
I'm still gauging whether I should polish and release it as a product, and would love some feedback and/or sign-ups: