Duolingo, the App That Always Wins the Battle for Your Attention(wsj.com)
wsj.com
Duolingo, the App That Always Wins the Battle for Your Attention
https://www.wsj.com/tech/personal-tech/duolingo-streaks-notifications-app-spanish-bc87d6e4
https://www.wsj.com/tech/personal-tech/duolingo-streaks-notifications-app-spanish-bc87d6e4
https://archive.is/v2bXN