I've been building a language learning app which uses AI voice chat to let people practice. Would that be something interesting for you to try out? It's all still rough, but we've been learning Japanese with it and its pretty cool.
If you're really interested, shoot me an email.
You can use it as supplement or do it standalone on your commute before a trip and end up with good pronunciation, vocab and a conversational skills.
What I've been building, with the help of a few language teachers, is our best guess at a really good way of learning new languages from the comfort of your home. It's not ever going to be perfect, but it is pretty good (at least so far in testing within our small group), and very cost-effective.
If you're interested in funding it, I'm happy to go live in Japan for a year :)