Comparison

Universal Zoom vs Stars Units Sizes Objects

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Universal Zoom

Explore the universe's vastness and intricacy through interactive visual comparisons. Seamlessly zoom from subatomic particles to the observable universe, gaining intuition about scale and size with stunning imagery and clear explanations.

Highlights
  • Seamless zooming across scales
  • Visual comparisons of objects
  • Jargon-free scientific explanations
  • Audio narration
  • Over 270 objects presented to scale
  • Multi-language support
Features
Currently charting
Read full description

The universe is endlessly vast. A single atom is impossibly small. And somewhere between those two extremes lies everything that has ever existed. We believe that feeling — the electric, spine-tingling sense of scale — belongs to everyone. Not just scientists. Not just students. Everyone. That's why we built Universal Zoom. WHAT YOU CAN DO • Zoom seamlessly from the Planck length to the edge of the observable universe — about 300 objects presented to perfect scale. • Compare any two objects side by side: how many Earths fit inside Jupiter? How does a virus measure up against a skyscraper? Instant, visual, intuitive. (No other scale app lets you do this.) • Go deeper with audio narration and short, accessible explanations — the facts that matter, in plain language. WHAT YOU'LL EXPLORE • Elementary particles — quarks, leptons, and bosons. Atomic nuclei, atoms, and DNA. Living cells. Animals and landmarks. Planets, stars, and galaxies. A deep dive into physics, biology, and astronomy — with short, plain-language articles that make even particle physics easy to grasp — in 40 languages, with metric, imperial, or powers-of-ten units. • Real high-resolution photos and electron microscope images, where possible. Original artwork for things that can't be photographed — like elementary particles and DNA structures. • No ads. No in-app purchases. Pure discovery. BUILT WITH YOU We're a team of two (Andrey and Oksana) from Canada who have poured a decade into this app because we genuinely love science. Most objects come from community suggestions — carefully fact-checked and updated with every new discovery. Over 200 more are already in the queue. FOR EDUCATORS Used by teachers worldwide to visualize scale, build measurement intuition, and turn abstract numbers into "aha" moments. Available at 50% off for schools via Apple School Manager (20+ copies). FOLLOW THE JOURNEY Sneak peeks and upcoming additions: @gamifyitapps on X, YouTube, and TikTok. Feedback and ideas: gamifyitapps.com/contact

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.

Screenshots

Universal Zoom4 screens
Stars Units Sizes Objects4 screens

Verdict

The call

The clearest difference is price: Stars Units Sizes Objects at Free against Universal Zoom's $5.99. Stars Units Sizes Objects also leads on iOS requirement (11.0 vs 15.5). Universal Zoom's advantage is rating (4.8 vs 4.2) and ads (none vs shown). On 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

Stars Units Sizes Objects is free to download; Universal Zoom costs $5.99 up front. Neither carries in-app purchases, so what you see is what you pay.

ReceptionRating · Positive reviews · Number of ratings

Universal Zoom holds the better App Store score, 4.8 against 4.2. That said, the two scores are not equally well evidenced: Universal Zoom has 363 ratings behind it against 5, so its average is the more settled of the two. Written reviews point the same way: 97% of Universal Zoom's written reviews are positive against 80% of Stars Units Sizes Objects's.

UpkeepUpdate frequency

Both ship on a similar rhythm, roughly every 4 months. The most recent releases landed on October 21, 2026 and September 22, 2026 respectively.

Scorecard8 real differences · 3 level
Universal Zoom versus Stars Units Sizes Objects: the parameters behind the verdict, then further details
ParameterUniversal ZoomStars Units Sizes Objects
Price$5.99Free — better
Rating4.8 (363 ratings) — better4.2 (5 ratings)
Positive reviews96.7% of reviews — better80.0% of reviews
Number of ratings363 — better5
Update frequencyEvery 4 monthsEvery 4 months
AdsNo — betterYes
In-app purchasesNoNo
MonetizationPaidAd-supported — better
Best chart rank#129 — better—
DevicesiPhone, iPad, iPod, Apple TV — betteriPhone, iPad, iPod
Requires iOS15.511.0 — better
Further details — not scored
Size175 MB124 MB
Age rating4+4+
DeveloperGamifyItMudarmeen Munlin

Customer experience

Universal Zoom

All ratings356 ratings
Positive95.5%
Neutral2.0%
Negative2.5%
Written reviews389 reviews
Positive96.7%
Neutral1.5%
Negative1.8%

Stars Units Sizes Objects

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

Bugs and requests

Universal Zoom

Reported bugs

3 issues
  • Incorrect information for some objects
  • Compatibility issues on older devices
  • Typos and minor errors in text

Requested features

5 requests
  • Add more objects and comparisons
  • Customizable object feature
  • Support for more languages
  • Ability to toggle between metric and imperial units
  • Search and filtering options

Stars Units Sizes Objects

Not enough reviews yet to summarise bugs or requests.

In-app purchases

None

Universal Zoom

No in-app purchases

None

Stars Units Sizes Objects

No in-app purchases

Questions

Is Universal Zoom free?
Universal Zoom costs $5.99, with no in-app purchases.
Is Stars Units Sizes Objects free?
Stars Units Sizes Objects is free to download, with no in-app purchases.
Which has better reviews, Universal Zoom or Stars Units Sizes Objects?
Universal Zoom is rated higher. Universal Zoom averages 4.8 out of 5 from 363 ratings, while Stars Units Sizes Objects averages 4.2 from 5 ratings.
Do Universal Zoom or Stars Units Sizes Objects have ads?
Stars Units Sizes Objects shows ads; Universal Zoom does not.
Which is updated more often, Universal Zoom or Stars Units Sizes Objects?
Universal Zoom ships an update every 4 months, and Stars Units Sizes Objects every 4 months. Most recently, Universal Zoom was updated on October 21, 2026 and Stars Units Sizes Objects on September 22, 2026.

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