The top level tabs have roughly stayed the same while the visual style has been tweaked to be cleaner and the owl has been redrawn.

The Clubs feature is being A/B tested against the Leaderboards tab (and some users aren't happy about it: Petition to save Clubs)

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Duolingo

Gamification: Badges
Change or add language
App Store screenshots
App icon change
Duolingo Plus
Asking for notiification permissions during onboarding
Learning experience
Top level tabs
Duolingo Clubs
Onboarding
Gamification: Streak, Lives and Gems
Gamification memes
Create profile

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Content Screens

Top Level Tabs
Top level pages
Top level tabs
Top level tabs