Gravity! vs Stars Units Sizes Objects
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Gravity!
Simulate the forces of gravity by flinging particles and observing their interactions. Create celestial bodies like planets and black holes, and customize their properties. Explore vast cosmic simulations with intuitive zoom and pan controls.
- Gravity simulation
- Particle interaction
- Create solar systems
- Add black holes
- Adjust particle properties
- Zoom and pan controls
Read full descriptionHide full description
This app simulates the effects of gravity. You can fling particles at each other and watch them interact. Create solar systems and galaxies! Make a planet and fling asteroids into it! Add a black hole and watch everything get sucked in! You can adjust the size, mass, and color of the particles! Zoom in and out and look around with two fingers! App Preview Music: "Mesmerizing Galaxy " Kevin MacLeod (incompetech.com) Licensed under Creative Commons: By Attribution 4.0 License http://creativecommons.org/licenses/by/4.0/
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
Read full descriptionHide 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
Verdict
The clearest difference is in-app purchases: Stars Units Sizes Objects at none against Gravity!'s 1. Stars Units Sizes Objects also leads on rating (4.2 vs 3.9) and iOS requirement (11.0 vs 15.6). Gravity!'s advantage is ads (none vs shown) and update cadence (every 2 months vs every 4 months). On price, review sentiment 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. Gravity! sells 1 one-off in-app purchase. Stars Units Sizes Objects asks for nothing beyond the download.
Stars Units Sizes Objects holds the better App Store score, 4.2 against 3.9. Both are backed by a comparable volume of ratings — 18 and 5 respectively. Written reviews point the same way: 74% of Gravity!'s written reviews are positive against 80% of Stars Units Sizes Objects's.
Gravity! ships an update every 2 months, Stars Units Sizes Objects every 4 months. The most recent releases landed on August 6, 2026 and September 7, 2026 respectively.
| Parameter | Gravity! | Stars Units Sizes Objects |
|---|---|---|
| Price | Free | Free |
| Rating | 3.9 (18 ratings) | 4.2 (5 ratings) — better |
| Positive reviews | 73.5% of reviews | 80.0% of reviews — better |
| Number of ratings | 18 — better | 5 |
| Update frequency | Every 2 months — better | Every 4 months |
| Ads | No — better | Yes |
| In-app purchases | Yes | No — better |
| Monetization | Free with in-app purchases | Ad-supported — better |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Requires iOS | 15.6 | 11.0 — better |
| Further details — not scored | ||
| Size | 17 MB | 124 MB |
| Age rating | 4+ | 4+ |
| Developer | Marc Davis | Mudarmeen Munlin |
Customer experience
Gravity!
Stars Units Sizes Objects
In-app purchases
Gravity!
- Gravity! Extended Edition$0.99
Stars Units Sizes Objects
No in-app purchases
Questions
Is Gravity! free?
Is Stars Units Sizes Objects free?
Which has better reviews, Gravity! or Stars Units Sizes Objects?
Do Gravity! or Stars Units Sizes Objects have ads?
Which is updated more often, Gravity! or Stars Units Sizes Objects?
Other comparisons
