While learning Japanese using a mix of comprehensible videos (I like cijapanese.com), podcasts, and shows, I've also been working on my own language learning podcast generator to smooth over plateaus and learn more specialized vocabulary. I'm getting more and more excited about it as a platform for experimentation with different teaching methods.
It's not available publicly yet, but works well for my purposes and I'm working on productionizing it. Sign-up page for updates: https://letmeknow.jkoff.ca/infinite-ci