Why learn a language when Autolingo can learn it for you! 
This extension adds a button to the top-right of every lesson. If you click this button, it will fully complete the lesson for you.
Additionally, if you are in the middle of the lesson, you can open the extension and click “Complete current challenge” to complete the current question.
This is likely to break if Duolingo updates their website, so please let me know if it’s not working so I can fix it!