Lesson planning shouldn't take longer than teaching the lesson itself. Here's how the builder actually works.
Give the lesson builder a topic, a grade level, and a duration, and it drafts a full lesson — objectives, a warm-up, guided practice, an independent activity, and a check for understanding. It's a first draft, not a final one, and it's designed to be edited, not obeyed.
The part teachers seem to like most isn't the generation — it's that every draft comes with alternate versions of the independent activity, pitched at slightly different difficulty levels, so differentiating for a mixed classroom doesn't mean starting from scratch three times.