Study on the bus, on a plane, in the dead zone: offline spaced repetition

The single most reliable way to remember something is to test yourself on it, just before you'd forget it. That's spaced repetition, and decades of research back it: retrieval practice beats re-reading, and spacing beats cramming. The problem was never the science. It's finding the minutes.

The minutes are already there

You don't need a free hour. Spaced repetition works in bursts of two or three minutes — exactly the dead time you already have and waste: the bus, the queue, the walk, the ten minutes before class. The catch: those are precisely the moments you often have no signal. A study app that needs the network is useless in a tunnel.

So we built Lumo's review to work fully offline.

Save a deck, drill it anywhere

On your phone, tap Save for offline on any note. Its flashcards and quizzes download to the device. From then on the Review tab works with the plane in airplane mode and the metro underground — no spinner, no "you're offline" screen. You swipe through cards, grade yourself, and the scheduler decides what you see next.

When you reconnect, your grades sync automatically in the background, so your schedule stays consistent across every device. Nothing you did offline is lost.

Grade with a swipe

Reviewing should feel light, not like data entry. Swipe a card the way it felt: easy, and it comes back in days; hard, and it returns soon. That single gesture is the whole loop — recall, judge, move on — and it's what makes a queue of forty cards take four minutes instead of a chore you avoid.

The algorithm does the remembering

You don't have to plan any of this. A spaced-repetition scheduler tracks each card's difficulty and your history, and surfaces cards right at the edge of forgetting — the point where a successful recall strengthens the memory most. Weak cards come back often; solid ones fade into the background until they're due. Your job is just to show up for a few minutes.

From a lecture to a habit

The whole point of generating flashcards in seconds is that the making stops being the bottleneck — so the only thing left is the reviewing, and offline review removes the last excuse for skipping it. A deck made today, drilled two minutes a day on your commute, is a chapter you'll still know at the exam.

Make your first offline deck from any note — try it in the public demo, then save it to your phone.