DIN Next Rounded in action on tinycards.duolingo.com

.content-1 { font-family: DINNextRoundedLTPro-Medium, sans-serif; font-size: 27px; font-style: normal; font-weight: normal; letter-spacing: normal; line-height: 40.5px; text-transform: none; color: #5C5C5C; }
.content-2 { font-family: DINNextRoundedLTPro-Regular, sans-serif; font-size: 18px; font-style: normal; font-weight: normal; letter-spacing: normal; line-height: 36px; text-transform: none; color: #898989; }
Found by @mikesten on 12 Mar 2017.

DIN Next Rounded