8 planets, 1 Sun
A living solar system
Watch all eight planets orbit the Sun on your home screen, then tap any one to fly in.
The solar system fits in your pocket.
Tap the Sun, spin through the planets and meet the moons. Fun facts, quizzes and badges for curious kids, with no ads and no sign-up.
Coming soon
Coming soon
For ages 6–12 · 19 languages · No ads
See what’s inside
Cosmo in numbers
- 21worlds to explore
- 234fun facts
- 80quiz questions
- 18badges to unlock
Fact-checked against NASA & ESA data (2026).
Inside the app
What's inside
-
8 planets, 1 Sun
-
21 worlds
21 worlds to explore
The Sun, 8 planets, 9 moons, 2 dwarf planets and the International Space Station. Every one has its own story and stats.
-
234 facts
234 fun facts
Did you know Saturn would float in a giant bathtub? Collect a new fact every day and build a reading streak.
-
80 questions
Quizzes that teach
80 questions across Planets, Moons, the Sun and Space Facts. Beat the timer, earn points and learn something new with every answer.
-
Side by side
How big is big?
Put planets side by side and see just how tiny Earth is next to Jupiter, and the Sun next to everything.
-
18 badges
Badges and levels
Unlock 18 badges and level up as you explore, read and quiz your way across the solar system.
Take a look around
Real screens from the current build of Cosmo.
21 worlds to explore 
234 fun facts 
Quizzes that teach 
How big is big? 
Collect every badge
Swipe or scroll sideways to see more screens.
Accessibility
Made for every young explorer
-
Easy-to-read text
Cosmo uses Andika, a typeface made for children learning to read, so letters like I, l and 1 never get mixed up.
-
Text that grows
Pick Small, Medium or Large text right in the app.
-
Calm motion
Cosmo respects your device's “reduce motion” setting.
-
In your language
Cosmo speaks 19 languages: English, Macedonian, German, French, Spanish, Italian, Portuguese, Dutch, Swedish, Norwegian, Danish, Finnish, Estonian, Latvian, Polish, Czech, Slovak, Slovenian and Croatian.
For parents
Screen time you'll feel good about
-
No ads. No sign-up. No tracking.
Cosmo has no advertising, no accounts and no analytics. Progress is saved only on your child's device. This website doesn't track you either.
-
Real science, fact-checked
Every fact and quiz answer is based on NASA and ESA data and was fact-checked in 2026. That includes the latest moon counts: Saturn has more than 290 moons!
-
Learning disguised as play
Streaks, badges and quizzes keep kids coming back, and every tap teaches something real.
-
Original, calming soundtrack
A gentle space theme and soft sound effects. You can switch both off in Settings.
Speaks your language
Choose one to see this page's headlines in it.
Questions from parents
What ages is Cosmo for?
Cosmo is designed for kids aged about 6–12, and curious grown-ups are welcome too.
Does Cosmo have ads or in-app purchases?
No. Cosmo has no ads and no in-app purchases.
Does my child need an account?
No. There is no sign-up and no login. Progress stays on the device.
Does it work offline?
Yes. All facts, quizzes, images and 3D models are built into the app, so everything works without an internet connection.
Where do the facts come from?
From NASA's planetary fact sheets, NASA Science and ESA, and they were fact-checked in September 2026. Space keeps surprising us, so we update the facts when new discoveries are confirmed.
Which devices does it run on?
iPhone and iPad (iOS 15 or later) and Android phones and tablets (Android 7.0 or later).
Ready for launch? 🚀
Download Cosmo and start exploring the solar system tonight.
Coming soon
Coming soon