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Life & fun · alternatives · 2026

24 alternatives to Sarthium

Learning Hub for Coding, Cosmos, Physics all at one place

Below are 24 products that do a similar job, ranked by how close each is in meaning and then by launch-day votes. Prices are shown for the 1 we have checked on their own sites, 1 of them free or with a free tier.

  1. 1

    Mobile game that teaches you the logic of coding.

    2018 · play.google.com · its alternatives →

  2. 2
    Atlas of Spacefree▲770

    Hello HN! Sharing a recent side project of mine, the Atlas of Space, that I built out to explore the Solar System. As a long-time space nerd, I realized recently that I didn't have a good intuition on the scale, speed, and relative orientation of the celestial bodies around us. So over the break I built out a kind of spatial Wikipedia to click around and learn about planets, moons, asteroids, and other bodies orbiting the Sun. The physics is all simulated in the browser using simple Newtonian mechanics. There's a lot left to do from here, including modeling objects in non-Keplerian orbits…

    2025 · atlasof.space · its alternatives →

  3. 3IM

    As you solve LeetCode questions, you can mark them as hard, medium, or easy. The tool will then recommend questions you should review based on (1) how hard the question was for you and (2) how much time has passed since you last reviewed it. I'd recommend normally attempting LeetCode problems and just marking them as hard, medium, or easy for you at first so the tool knows which problems to recommend you review! Here's the theory behind spaced repetition and learning if interested: https://www.codecademy.com/article/spaced-repetition

    2024 · lanki.xyz · its alternatives →

  4. 4
    Enlight▲281

    Learn to code by building projects

    2016 · enlight.nyc · its alternatives →

  5. 5

    A new way to explore and learn about the world

    2022 · kinnu.xyz · its alternatives →

  6. 6
    Mapedia▲77

    The best place to start learning something new

    2022 · mapedia.org · its alternatives →

  7. 7
    Spatium▲182

    Hi there, humans! I'm excited to announce Spatium! I'm a big fan of any topic related to our universe. I'm also a developer, so I've put these things together and I built this new tab Chrome Extension for space lovers, astronomy fans, and science geeks like me. If you enjoyed it, please spread some love <3 FEATURES • Space images • Every day, get a fascinating image of our universe. Enjoy pictures of stars, planets, moons, galaxies, nebulae, comets and more right on your browser tab. • Sun Widget • Find out when the sunrise, sunset, first and last light times will be precisely at your…

    2021 · spatium.earth · its alternatives →

  8. 8

    App that creates an acoustic star map of the universe

    2021 · its alternatives →

  9. 9FS

    Hi HN, I'm Djoumé. I've been a developer for over 20 years, and like a lot of you I've been coding almost exclusively through an agent in the past few months. It's been amazing to vibe code prototypes in any stack, but when it comes to building something reliable&#x2F;scalable, I couldn't effectively guide the agent unless I knew the technology. And the scariest part is that I'm seeing a lot of my technical skills decreasing due to AI coding. Reflecting on my journey, I also worry about how the new "AI native" generation of software developer is going to acquire technical depth. So I built…

    Jun 2026 · fata.dev · its alternatives →

  10. 10
    Heimdall▲126

    Hey HN, We built Heimdall (heimdallspace.com) because the existing tools for space situational awareness are genuinely painful to use: clunky interfaces, fragmented data sources, slow rendering. The ones that aren't are locked behind enterprise solutions. We thought the foundation of this should be open and accessible. The goal is a satellite observability platform: one place that gives operators complete, real-time insight into their assets and the orbital environment around them. Today's release is the foundation—aggregating and rendering the full public space catalog (30,000+ objects) in…

    Feb 2026 · heimdallspace.com · its alternatives →

  11. 11

    Spacemacs for Neovim—link to layers 👉. Contribute to Tehnix/spaceneovim development by creating an account on GitHub.

    2016 · github.com · its alternatives →

  12. 12

    A space game with a mix of strategy, tactics and coding.

    2015 · its alternatives →

  13. 13
    Edabit▲101

    It's like Duolingo for learning to code.

    2017 · edabit.com · its alternatives →

  14. 14EL
  15. 15

    Learn math by exploring the Solar System. Ad-free & Privacy

    Apr 2026 · apps.apple.com · its alternatives →

  16. 16

    A game about gravity and asteroids

    2014 · apps.apple.com · its alternatives →

  17. 17

    Developers, freelance projects, homework help

    2023 · codethis.co · its alternatives →

  18. 18

    Why code when you can NoCode?

    2022 · its alternatives →

  19. 19

    A tediously accurate scale model of the solar system

    2014 · joshworth.com · its alternatives →

  20. 20

    My cousin and I love the Terraforming Mars board game. But we'd often get overly excited and knock our pieces off of our boards, losing track of our progress. So I digitised it. It comes with a few cool features like resource conversions (e.g. converting plants to greenery), production phase, offline, mobile-friendly and keeps track of the history using the browser history itself. Sharing this here in case there are any other TM fans that could also find some use in this :)

    2024 · terraforming-mars-player-board.netlify.app · its alternatives →

  21. 21

    The design platform for complex engineering systems

    Apr 2026 · systellar-space.com · its alternatives →

  22. 22HO

    3D gravity and space Simulator. Explore and play around with the force of gravity in the context of an array of scenarios from our solar system and beyond. You can add planets, delete the Sun, change the value of the gravitational constant or simply lean back and enjoy the dazzling beauty of the pen

    2018 · thehappykoala.github.io · its alternatives →

  23. 23

    How would you create a new world?

    2018 · goarchitect.com · its alternatives →

  24. 24

    I built StellarSnap as a calm, ad-free space to explore NASA’s Astronomy Picture of the Day (APOD) and learn astronomy along the way. What it includes: - A clean APOD archive browser with a Random APOD button - A growing Glossary with term highlighting across the site - A 2D Orbit Simulator where you can test satellite motion with real physics - A deeper Encyclopedia, still early, but expanding - Subtle touches like “see past APODs using this term” - And more to come It’s entirely ad-free, cookie-free, and not affiliated with NASA, but I was honored to have StellarSnap mentioned on the…

    2025 · stellarsnap.space · its alternatives →

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Ranked by how close each launch is in meaning, then by votes. Prices were read from each product’s own site when checked and can change. Refine with your own description →