Ever struggled to practice English reliably when you’re on a plane? In this lesson you’ll learn how to design and use an offline micro‑drill app so you can run secure, repeatable 1–15 minute practice sessions during flights and sync results after landing. You’ll get a concise rationale, a prioritized feature and UX checklist, real in‑flight examples, and targeted exercises to test your understanding — all presented with discreet, data‑driven guidance you can act on immediately.