language practice and correction

I'm new to this and have some beginner questions: I've got a long daily commute and need to improve my German. I would like something that I can chat with, and get corrections on things I'm repeatedly doing wrong (grammar, pronouns, etc). The internet connection isn't great along the route so I'm looking at something I can have running locally on a laptop. Are there any plug an play options out there? From what I have read so fa