Five questions picked fresh each day from space, history, food, animals, sports and more, and a fun fact of the day. Free, no sign-up, back tomorrow with five more.
Pick an answer and the fact behind it appears. The set changes at midnight where you are.
Do you know this one?
Tap an answer, or press 1, 2 or 3; Enter for the next question
It rains diamonds on Neptune and Uranus.
Deep inside the ice giants, crushing pressure squeezes carbon out of methane and compresses it into diamonds that sink toward the core.
Source: NASA
At midnight where you are: the five questions and the fun fact are picked by today's date, so everyone on the same day gets the same set, and tomorrow brings five new ones. Come back daily, or let the Lock&Learn widget bring a question to every screen-wake.
Yes. Each of the 12 trivia topics has twenty questions to play straight through, and the app holds over a thousand more.
Yes. Read them out, print the page (the right answers are marked) or play the quiz on a shared screen. Each question has one right answer and two plausible wrong ones, and the fact under it gives you something to say after the reveal. Please do not republish the questions elsewhere.
Every fact names its source under the answer, from space agencies and museums to encyclopedias and published research. Lock&Learn writes each one as a teaser question with three answers, and the fact that settles it.
Install Lock&Learn, then touch and hold your Lock Screen, tap Customize, tap the widget area and choose Lock&Learn. A question waits on every screen-wake; you guess, tap, and reveal the verified fact behind the answer. Pick the topics you like and the widget rotates through them.
Yes. Lock&Learn is free on iOS: every topic opens with a free preview and another question unlocks daily. Lock&Learn+ is an optional upgrade that opens every topic in full.