This looks interesting to me, but I've been looking for a language learning app that goes beyond flash cards and SRS as its core teaching concept. SRS is great for learning individual vocabulary in a vacuum, but kind of falls apart when you need to teach bigger concepts like number systems, grammatical theory, or conjugation rules. If you've already been taught the rules, then an SRS app like Wanikani can be a really great supplement to that, but it's not going to serve as a full learning experience.

This is where I find Duolingo and its imitators really frustrating, and I've been looking for a higher-effort product that actually uses subject-appropriate teaching strategies, and not treating SRS as a silver bullet.

The "puzzle" feature here looks interesting, so I'd like to see how integrated it is with the concepts, vs. being another view onto "word <-> translation" and SRS.