COSMOS vs DeckLearn

COSMOS is a solar system you hold in your hand. This is not a decoration. Every planet sits exactly where it is right now, computed from real orbital mechanics. Where is Jupiter tonight? How are Saturn's rings tilted? Open the app — the answer is there. - REAL ORBITS Positions of all 8 planets and the Moon are computed from Keplerian orbital elements in real time. Scrub through time to see the sky 10 years from now — or the day you were born. - PHOTO-REAL TEXTURES Saturn's rings, Jupiter's Great Red Spot, sunspots and solar granulation — every texture is generated on your device and stays crisp as you zoom. - CONTROL TIME From one second = hours, to one second = years. Watch the Moon change phase and the planets trace their orbits with your own eyes. - EXPLORE FREELY Pinch and swipe from outside the solar system down to a planet's face. Tap any body for details. - DESIGNED WITH RESPECT - No ads, ever - No in-app purchases — one simple price - Works fully offline, on a plane or on a mountain - Collects zero personal data For curious kids asking "why?" For stargazers who want a quiet moment of awe. The real universe, in your pocket. LANGUAGES English, Japanese, Simplified Chinese, Korean, Spanish, French, German

Turn any spreadsheet into a flashcard deck, then study until every card sticks. DeckLearn imports a plain CSV file — a column of questions, a column of answers — and turns it into a deck you can quiz yourself on. No accounts, no subscription, no internet connection. Just your cards and your progress, on your phone. IMPORT IN SECONDS Pick a CSV and DeckLearn does the rest. It detects header rows automatically, handles quoted fields and commas inside answers, and shows you a live preview before anything is created. Files with extra columns work too — you choose which two become the front and back of each card. STUDY THE WAY THAT WORKS Three modes, switchable any time: • Shuffle — a fresh random order every pass • In Order — exactly the order from your file • Weakest First — the cards you keep missing come first New cards always come before ones you've seen, and the same card never appears twice in a row. MASTERY, NOT GUESSWORK Every card moves through New, Incorrect, Correct, Mastered. A card is mastered once you get it right several times in a row — three by default, adjustable per deck. Miss it, and the streak resets. Cards you've mastered leave the rotation so you spend your time on what you don't know yet. SPOT CHECKS KEEP IT HONEST Mastered cards get quietly mixed back in now and then to make sure they really stuck. Tune how often, or switch it off entirely. TWO-WAY CARDS Studying a language? Turn on reversible cards and DeckLearn will quiz you in both directions — term to definition and back again. Each direction tracks its own streak, and a card counts as mastered only when both are solid. Focus on one direction at a time whenever you want. SEE YOUR PROGRESS Every deck shows a live mastery ring and a colour-coded breakdown of where your cards stand. A statistics dashboard totals it all up across every deck — cards mastered, answers given, overall accuracy, and the running Energy count of every correct answer you've ever made. BUILT-IN SAFETY NET Graded a card wrong by accident? One tap takes it back. Reset a single card, or an entire deck, whenever you want a clean start. PRIVATE BY DESIGN DeckLearn has no accounts, no ads, no analytics, and no network access of any kind. Your decks never leave your iPhone. There is nothing to sign up for and nothing to opt out of. Requires iPhone running iOS 17 or later.