Langua is a nice app with more features than ISSEN. We focus on the voice chats, and I think our tech is better (intelligence, latency, realtime flow, voices, etc), especially for non english/spanish.

We are aiming to create a long term companion/tutor that gets to know you more and more, and can create customized curriculums, lessons, etc.

Co-founder of Langua here.

Congratulations on the launch! Very cool take on combining the structure of a personalized curriculum with voice chats.

Langua has both a chat mode and a voice mode for uninterrupted conversations to give learners flexibility. Our initial approach has been less structured which is ideal for intermediate / advanced learners. We have had a lot of demand from beginners for more structured and personalized learning paths, so we're rolling those out as well.

Best of luck with with ISSEN.