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)

More screenshots from‏‏‎ ‎

Duolingo

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

More‏‏‎ ‎

Content Screens

Duolingo Clubs
Top level tabs
Top level tabs
Top level tabs