My Take
Scratch can be used anywhere from Kindergarten up to college grad. level. All ability levels can be challenged. Scratch is great for getting students to understand how algorithms and programming works. They get to use their own creativity and complete projects with the teacher as a facilitator. This is my favorite unit to teach because you can really see how the students start with zero knowledge and build upon it until they are creating beautiful finished products.
How I Use It
Each student creates their own account. I begin with the "My 1st Scratch Program" and then I teach concepts as I move into the next lesson. In this one, students create (or upload) Sprites representing each letter of their name and they animate each letter, add looks, sounds, movements, etc. Basic level students and advanced level students can each get as much as needed from these projects.