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

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

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Content Screens

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