Comparison

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.

Head to head
About

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.

Highlights
  • 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
Features
Read full description

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.

About

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.

Highlights
  • 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
Features
Read full description

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

Stars Units Sizes Objects4 screens
DIY Solar System4 screens

Verdict

The call

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

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

ReceptionRating · Positive reviews · Number of ratings

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.

UpkeepUpdate frequency

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.

Scorecard5 real differences · 5 level
Stars Units Sizes Objects versus DIY Solar System: the parameters behind the verdict, then further details
ParameterStars Units Sizes ObjectsDIY Solar System
PriceFreeFree
Rating4.2 (5 ratings)4.5 (16 ratings) — better
Positive reviews80.0% of reviews100.0% of reviews — better
Number of ratings516 — better
Update frequencyEvery 4 monthsEvery 2 months — better
AdsYesNo — better
In-app purchasesNoNo
MonetizationAd-supportedFree — better
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS11.0 — better12.0
Further details — not scored
Size124 MB180 MB
Age rating4+4+
DeveloperMudarmeen MunlinThe Lawrence Hall of Science

Customer experience

Stars Units Sizes Objects

All ratings3 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews5 reviews
Positive80.0%
Neutral0.0%
Negative20.0%

DIY Solar System

All ratings16 ratings
Positive87.5%
Neutral0.0%
Negative12.5%
Written reviews8 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

None

Stars Units Sizes Objects

No in-app purchases

None

DIY Solar System

No in-app purchases

Questions

Is Stars Units Sizes Objects free?
Stars Units Sizes Objects is free to download, with no in-app purchases.
Is DIY Solar System free?
DIY Solar System is free to download, with no in-app purchases.
Which has better reviews, Stars Units Sizes Objects or DIY Solar System?
DIY Solar System is rated higher. Stars Units Sizes Objects averages 4.2 out of 5 from 5 ratings, while DIY Solar System averages 4.5 from 16 ratings.
Do Stars Units Sizes Objects or DIY Solar System have ads?
Stars Units Sizes Objects shows ads; DIY Solar System does not.
Which is updated more often, Stars Units Sizes Objects or DIY Solar System?
Stars Units Sizes Objects ships an update every 4 months, and DIY Solar System every 2 months. Most recently, Stars Units Sizes Objects was updated on September 7, 2026 and DIY Solar System on June 3, 2026.

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