Boom cards is a tool to create activities that you could post for your students in SeeSaw or Google Classroom.

Let’s take a quick look at Boom Cards. Boom Cards lets you create interactive lessons and activities for your students. Boom cards provides instant feedback and checks answers for you.

There are lots of possibilities for exciting activities in Boom Cards however the free version is purely for exploring how to make one.
The free account is useless for assigning to students and trying to use in class. Pricing is low though.