I really like to use the MRU interactives on the board with students voting on mini whiteboard or picking students to answer. The graph ones in particular are useful as they offer a dynamic visual that I haven't been able to find as clearly elsewhere, but I also really like the examples they use in 'Whats included in US GDP' as they are carefully chosen to address misconceptions. The 'demand/supply vs quantity demanded/supplied' are also great for misconceptions.
If you wanted to set them for homework, there is an option for students to download of JPEG image of their score which they can submit to you.
Here are the interactives they have at the time of writing:
Price Ceilings Price Floors Consumer and Producer Surplus Shifts in Supply or Demand (3 Sets) Functions of Money Winners and Losers of Inflation Trade Tariffs Calculating Inflation Winners and Losers of International Trade Graphing Gains From Trade Holiday Edition: What’s Included in U.S. GDP? Holiday Edition: Shifts in Supply or Demand Shifts in Both Supply and Demand Curves What’s Included in U.S. GDP? Change in Supply vs. Change in Quantity Supplied Change in Demand vs. Change in Quantity Demanded Change in Demand vs. Change in Quantity Demanded (Valentine’s Day Edition)