I have used Duolingo for a couple years now and and was so disappointed to see a sexually explicit ad for a game called "Choices:***" which was preceded by the message "This ad helps keep education free". Knowing that my children use this app in their language programs at school, I cant believe that the app developers would allow such an ad to show up within their app. It featured a woman walking in on her naked husband in bed with another woman. It offered the wife role player a set of choices: smash everything or storm out. I was just dumbfounded by this obvious lack of regard for our children.
Riles Risto about Duolingo Learn Many Languages for Free, v5.0.14