How I Use It
I use Desmos in two different ways. First, I use it for classroom demonstrations: everything from showing examples of graphs, to demonstrating how changing parameters affects graphs, to posing critical-thinking questions to my class. Second, this is one among a collection of digital tools I suggest as resources for students to use as they work on projects and homework.
My overall opinion of this tool is that it has great potential to encourage creative, critical thinking in motivated students. In addition, it is a very nice to use for instruction for all students. Motivated students will be able to use the Desmos calculator on their own to discover many of the concepts we teach about functions. However, students who are not as strong at mathematics and/or struggle with abstract thinking, may also struggle with Desmos if asked to use it independently (there could be more built-in support for beginning students). Desmos is lacking support for beginning students. That said, this is a really nice tool for teacher-directed instruction that generates a lot of participation from students at all levels.