Stars Units Sizes Objects vs Orbit
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.
Orbit
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The app is an accurate interactive simulation of the solar system that allows you to explore the movement of the planets and the Moon around the Sun in a simplified, dynamic model based on real astronomical calculations. The app uses Kepler’s equations of orbital motion to display the positions of the planets realistically, with the ability to track their changes over time live and in real time. Features * Realistic simulation of the motion of all planets in the solar system * Ability to switch between a heliocentric or geocentric model * Control the date and view planetary positions on any day * Smooth automatic time progression * Relative simulation of the Moon’s orbit around Earth * Dynamic space background that reflects the depth of the universe * Smooth performance with real-time animation updates * Simple visual design that supports educational understanding of the solar system *Add alerts for future astronomical phenomena. Scientific Concept The app is based on: * Kepler’s laws of planetary motion * Solving Kepler’s equation to determine the true position of planets * Calculating relative orbital distances for each planet * Simulating motion based on the number of days since the year 2000 (Epoch J2000) Objective This app is designed as an educational and interactive tool to help users understand how planets and the Moon move in a simple and engaging visual way, while maintaining scientific accuracy as much as possible.
Screenshots
Verdict
The clearest difference is price: Stars Units Sizes Objects at Free against Orbit's $0.99. Stars Units Sizes Objects also leads on iOS requirement (11.0 vs 15.6). Orbit's advantage is ads (none vs shown) and update cadence (monthly vs every 4 months). On 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
Stars Units Sizes Objects is free to download; Orbit costs $0.99 up front. Neither carries in-app purchases, so what you see is what you pay.
Stars Units Sizes Objects ships an update every 4 months, Orbit monthly. The most recent releases landed on October 24, 2026 and October 27, 2026 respectively.
| Parameter | Stars Units Sizes Objects | Orbit |
|---|---|---|
| Price | Free — better | $0.99 |
| Rating | 4.3 (6 ratings) — better | — |
| Positive reviews | 80.0% of reviews | — |
| Number of ratings | 6 — better | — |
| Update frequency | Every 4 months | Monthly — better |
| Ads | Yes | No — better |
| In-app purchases | No | No |
| Monetization | Ad-supported | — |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Requires iOS | 11.0 — better | 15.6 |
| Further details — not scored | ||
| Size | 124 MB | 14 MB |
| Age rating | 4+ | 4+ |
| Developer | Mudarmeen Munlin | Omran Adam |
In-app purchases
Stars Units Sizes Objects
No in-app purchases
Orbit
No in-app purchases
Questions
Is Stars Units Sizes Objects free?
Is Orbit free?
Do Stars Units Sizes Objects or Orbit have ads?
Which is updated more often, Stars Units Sizes Objects or Orbit?
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