Blackbird lessons are arranged in progressive units. From the first lesson students are building a game they can customize to their heart's content. When they've finished all of the lessons students can move onto a "workshop" where they can work on independent projects that you can observe from your teacher dashboard in Blackbird.
There were a few features that stood out to me during my first run-through of Blackbird. First, students can get choose how much guidance they get on each lesson. Second, students' progress is locked in place as they go. Third, from your teacher dashboard you can see how much time your students spend on each activity.
Students can use just the basic instructions for each lesson or click on the definitions and "deep dives" embedded within the instructions. Those definitions and deep dives give students an explanation of what they're writing and puts the explanation into an applicable context.
Blackbird units are composed of progressive lesson sequences. When a student completes a lesson with 100% accuracy the code they wrote for that lesson is locked. It's locked because the next lesson will build upon their correctly written code. Locking the previously written code in place prevents students from accidentally changing their existing code and thereby impacting what they're currently working on.
Blackbird - How It Works from Blackbird on Vimeo.Applications for Education
While it's helpful to have some prior coding experience, Blackbird can be used by teachers who don't have any prior coding experience. Blackbird provides detailed tutorials and lesson guides for teachers who don't have coding experience. Furthermore, teachers can do the exact same lessons and activities as their students to learn alongside them.