YouTube Fridays devotes a small fraction of class time to student-selected videos related to the course topic, e.g., thermodynamics. The students then write and solve a homework-like problem based on the events in the video. Three recent pilots involving over 300 students have developed a database of videos and questions that reinforce important class concepts like energy balances and phase behavior. A set of example problems and videos are presented from a sophomore-level engineering thermodynamics course and a sophomore-level material and energy balances course. Student evaluations found a vast majority (79%) of the students felt better at relating real world phenomena to thermodynamics from participating in YouTube Fridays. Overall, YouTube Fridays is a student-led activity that provides practice of problem solving on open-ended, course related questions.