HOW DUOLINGO USED GAMIFICATION TO IMPROVE NEXT-DAY RETENTION

Summary from the TLDR Marketing newsletter

Duolingo improved next-day retention from 47% to 55% by using challenges and other gamification features. The app packages accomplishments as a “challenge”, which is either a high-level goal (e.g. "Learn Vietnamese") or a smaller goal (e.g. "study Vietnamese 7 days in a row). Duolingo provides visual motivations to show daily progress and uses external reminders to drive users back to the app.