The Observatory is the vocabulary app for curious minds. Every day, a new word is waiting for you.

Focus the viewfinder to discover it, learn what it means, how it's used and where it comes from, and then put it to the test.

── THREE CHALLENGES PER WORD ──
Comprehension, Usage and Mastery: true or false, pick the sentence, spot the odd one, fill in the blank, match the pairs, spelling and stress. Every answer comes with an explanation. Mastery is hard and worth double.

── YOUR ATLAS ──
Every word you discover becomes a star. Watch your galaxy grow, with a constellation for each category, binary stars that belong to two of them, search and a map.

── LIBRARY, CATALOGS AND REVIEW ──
All your words in one place. Sort them into your own catalogs, with notes. Review asks you about your words again right before you'd forget them, and it earns you points.

── KEPLER'S STAR CATALOG ──
Explore regions of the sky and add extra words to your galaxy.

── 3D COMPANIONS ──
Kelvin the turtle, Vera the octopus, Sagan the fox and their friends react to your answers in 3D. Dress them up with hats, glasses, scarves, things to hold and animated auras, all with the points you earn.

── STREAKS AND FRIENDS ──
Keep your streak alive, with a reminder before you lose it. Climb the weekly table with your friends and the Best streaks ranking at the space station.

── IN ENGLISH AND SPANISH ──
More than 20 categories, from everyday language to mythology, philosophy and astronomy, with the whole app in both languages.

3D characters and their wardrobe require a compatible device. On other devices, characters are shown as pictures and the wardrobe is not available.

Free to download, with ads. No subscription: everything in the app is unlocked with the points you earn.