I mean, lead a horse to water. I had 3 years of enforced language learning in high school. I barely learned any conversational Spanish. These sorts of apps are supplemental, otherwise paying some $10 subscription to learn a new language would be a steal.

It's best treated as reading some motivational quote in the morning. Gets you out of bed and into the mood but it won't carry you through life alone. Is that worth $10/month? Depends on the person, but it would be for me if I was being serious.