I tried a few during COVID and didn’t get very far. Some companies were offering their content for free during the pandemic. At first I was ambitious, trying to tackle Japanese, then Swedish, finally Spanish. Now I use spanishdict.com. It’s free.
Truthfully, I don’t think it’s that good. It couldn’t have taught me the language from scratch, but I’ve picked up enough Spanish over the years from television to do okay with the exercises, and every little bit of practice helps.
Teaching Company courses (available through online streaming or by ordering the discs from the company) are also pretty good, but I’d rather do exercises on the computer, rather than in a workbook.
What I found is once you learn a Slavic language, like Polish or Russian, it’s fairly easy to pick up the other ones, like Czech, Slovak, Serbo-Croat, etc.