Stars Units Sizes Objects vs DIY Solar System
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Stars Units Sizes Objects
Explore the vastness of the universe, from the smallest particles to the largest cosmic structures. Compare object sizes, view detailed images, and perform unit conversions across a wide range of astronomical scales. Learn about stars, galaxies, and the incredible distances between them.
- Compare object sizes
- View object images
- Pinch/Zoom and Pan images
- Unit conversion for distances
- Explore scales from Planck length to observable universe
- Learn about stars and galaxies
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Size of the smallest to largest objects and stars. Compare the size of objects in the universe. Object images. Pinch/Zoom image. Pan/Move image. Rotate image. Double tap to reset an image. From the smallest to the largest one. From planck length to observable universe. From Yoctometre, Zeptometre, Attometre, Femtometre, Picometre, Nanometre, Micro, Millimetre, Centimetre, Metre, KiloMetre, Lightyear, Parsecs, Billion Lightyears to 93 Billion Lightyears. Size of objects, particles, atoms, cells, stars and galaxies. Get to know the stars. Get to know the spaces. get to know the universe. How small is this world. How big is the universe. And How great is the creator. How far is the star distance from earth. Two way 18 distance unit conversion. planck length, yoctometer, zeptometer, attometer, femtometer, picometre, nanometre, micrometre, Millimeter, Centimeter, Meter, Kilometer, Inch, Foot, Mile, Astronomical, Lightyear, Parsecs. Perform auto conversion when picker is changed. Share conversion result. Reset unit convertor.
DIY Solar System
Explore the solar system with interactive activities and an augmented reality planet walk. Learn about space travel, design a moon base, and identify celestial objects. Developed by leading science institutions, this app makes learning about space engaging for families and educators.
- Interactive space activities
- Augmented reality planet walk
- Design a moon base
- Grow a space garden
- Control a Mars rover
- In or Out space game
- NASA imagery
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DIY Solar System makes it easy for families and educators to explore the solar system from anywhere, anytime! The app was developed by the Children’s Creativity Museum, Sciencenter, and Museum of Life and Science, in partnership with UC Berkeley’s The Lawrence Hall of Science. INTERACTIVE ACTIVITIES DIY Solar System includes 11 easy-to-use activities to learn about space travel, living in space, and the unique objects that make up the planetary system we call home. Design a Moon base, grow your own space garden, or experience what it’s like to control a rover on Mars! Each activity includes step-by-step instructions that have been tested by educators, kids, and families. Activity materials are easily available and inexpensive—you may already have many of them in your home! AUGMENTED REALITY PLANET WALK Don’t have the time to travel several billion miles to reach Neptune? Try dropping a scale version of the solar system outside your home to start a walk that will show you planets, dwarf planets, and asteroids. At each stop, examine the space object up close using real images from NASA. Don’t forget to take a space selfie with your favorite planet! IN OR OUT GAME Quickly scan awe-inspiring images of space objects from NASA’s Earth and space observatories to decide if the objects are in or out of the solar system. While the solar system is vast, it only represents a tiny corner of the universe. After you have mastered your solar system knowledge, challenge yourself to a new round of objects in or out of our home galaxy, the Milky Way. Funding Source This work was supported by NASA under award number 80NSSC21M0082. Any opinions, findings, conclusions, or recommendations expressed in these programs are those of the author and do not reflect the views of NASA. Compatibility Requires iOS 12.0 or later. Compatible with iPhone and iPad. Rated 4+.
Screenshots
Verdict
The clearest difference is ads: DIY Solar System at none against Stars Units Sizes Objects's shown. DIY Solar System also leads on rating (4.5 vs 4.2) and review sentiment (100% vs 80%). On price, update cadence, in-app purchases and device support there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. Neither carries in-app purchases, so what you see is what you pay.
DIY Solar System holds the better App Store score, 4.5 against 4.2. Both are backed by a comparable volume of ratings — 5 and 16 respectively. Written reviews point the same way: 80% of Stars Units Sizes Objects's written reviews are positive against 100% of DIY Solar System's.
Stars Units Sizes Objects ships an update every 4 months, DIY Solar System every 2 months. The most recent releases landed on September 7, 2026 and June 3, 2026 respectively.
| Parameter | Stars Units Sizes Objects | DIY Solar System |
|---|---|---|
| Price | Free | Free |
| Rating | 4.2 (5 ratings) | 4.5 (16 ratings) — better |
| Positive reviews | 80.0% of reviews | 100.0% of reviews — better |
| Number of ratings | 5 | 16 — better |
| Update frequency | Every 4 months | Every 2 months — better |
| Ads | Yes | No — better |
| In-app purchases | No | No |
| Monetization | Ad-supported | Free — better |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Requires iOS | 11.0 — better | 12.0 |
| Further details — not scored | ||
| Size | 124 MB | 180 MB |
| Age rating | 4+ | 4+ |
| Developer | Mudarmeen Munlin | The Lawrence Hall of Science |
Customer experience
Stars Units Sizes Objects
DIY Solar System
In-app purchases
Stars Units Sizes Objects
No in-app purchases
DIY Solar System
No in-app purchases
Questions
Is Stars Units Sizes Objects free?
Is DIY Solar System free?
Which has better reviews, Stars Units Sizes Objects or DIY Solar System?
Do Stars Units Sizes Objects or DIY Solar System have ads?
Which is updated more often, Stars Units Sizes Objects or DIY Solar System?
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