Friendly introduction, not certification. Use fictional data and sandbox actions. These primary sources were inspected on 14 October 2026. Products and APIs change; focus on principles and verify current SDK docs.

There are no AI/API calls in these lessons. Download the HTML file to learn offline; the live website needs a connection to load. Optional source links need internet. Some phone file viewers do not run interactive HTML; open it in a supported browser, or use the reflowable EPUB edition in your reading app. No tracking, remote assets or API calls. Local progress is tied to this browser/file or site—not synced between devices. Reading/quiz time estimates exclude building.