The curriculum is arranged linearly as a timeline with tests interspersed in between

There are posts by other learners and mini "games" that help you test your skills

Add friends to compete with. You can search by name or find them from facebook

Achievement leveled up modal

Gamification badges and progress

You can join language clubs to practice with other learners

Duolingo Plus lets you download lessons offline and removes ad. You can start with a 7 day trial

It quizzes you with audio and visual questions to make you understand and to increase recall

Bottom sheet for wrong answer

Tapping an item in Following to see stories in that item

Top level tabs

Recipe detail screen. When you tap add to cookbook, it prompts you to login or signup

Opening a project. Coach mark for swiping to go between projects