Comparison

RelativityTheory vs Simple Orbit Simulator

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

Head to head
About

RelativityTheory

Features
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Introducing and explaining the mysterious phenomenon derived from the theory of relativity. In particular, we will detail the changes in the way time progresses. The interstellar flight screen shows how time progresses in response to rocket speed. Shows the difference in how time progresses between rockets and the earth in space travel. The GPS screen shows that gravity changes the way time progresses.

About

Simple Orbit Simulator

Features
Read full description

Simple Orbit Simulator brings the elegance of Einstein's general relativity to your fingertips. Watch two celestial bodies dance under the influence of gravity β€” not as a textbook approximation, but as a true Schwarzschild geodesic simulation β€” the same physics that governs real planets, stars, and black holes. Real Physics, Visually Beautiful Unlike typical orbit simulators that use Newtonian gravity, Simple Orbit Simulator traces actual curved-spacetime paths. Every orbit is a genuine geodesic of the Schwarzschild metric. The result: Mercury-style perihelion precession that slowly paints a rosette pattern on screen, gravitational time dilation that deepens as the planet plunges toward the star, and event horizon dynamics that are physically meaningful β€” not just decorative. Black Hole Mode Switch to Black Hole Mode and watch a supermassive compact object warp the simulation. The event horizon, photon sphere, and innermost stable circular orbit (ISCO) become visible boundaries. Push the planet too close and it crosses the point of no return. Accretion disk glow and a dynamically warped spacetime grid make the physics viscerally tangible. Full 3D Orbits Tilt the orbital plane with the inclination slider and drag the canvas to rotate the camera freely. Horizontal drag changes the azimuth β€” spinning the scene left and right. Vertical drag changes the elevation β€” from a top-down view to edge-on. A circular orbit becomes an ellipse, a line, or a spiral rosette depending on your viewpoint. Physics is computed in full three-dimensional space. Live Relativistic Metrics Track real-time data as the simulation runs: β€’ Gravitational time dilation factor β€’ Accumulated proper time of the orbiting body β€’ Lorentz gamma factor β€’ Orbital velocity as a fraction of the speed of light β€’ Perihelion precession angle in degrees β€’ Orbits completed Explore and Experiment Adjust star mass, planet mass, and orbital distance with intuitive logarithmic sliders. See how increasing the star's mass deepens the gravitational well. Increase separation and watch relativistic precession shrink as GR effects fade with distance. Combine an inclined orbit with Black Hole Mode for a dramatic 3D plunge trajectory. Built for Clarity Every design decision prioritises understanding over complexity. The simulation uses scaled constants so relativistic effects are visible at screen scale β€” preserving all qualitative behaviour predicted by general relativity in a form humans can actually see. Simple Orbit Simulator is for students, educators, curious minds, and anyone who has ever looked up at the night sky and wondered what holds it all together.

Screenshots

RelativityTheory2 screens
Simple Orbit Simulator4 screens

Verdict

The call

The clearest difference is update cadence: Simple Orbit Simulator at every 3 days against RelativityTheory's every 3 weeks. RelativityTheory's advantage is iOS requirement (14.4 vs 18.2). On price, ads, in-app purchases and device support there is nothing between them.

Scored on Price Β· Rating Β· Positive reviews Β· Number of ratings Β· Update frequency Β· Ads Β· In-app purchases Β· Monetization Β· Best chart rank Β· Devices Β· Requires iOS

CostPrice Β· In-app purchases Β· Ads Β· Monetization

RelativityTheory costs $0.99 and Simple Orbit Simulator $0.99 up front. Neither carries in-app purchases, so what you see is what you pay.

UpkeepUpdate frequency

RelativityTheory ships an update every 3 weeks, Simple Orbit Simulator every 3 days. The most recent releases landed on September 13, 2026 and September 7, 2026 respectively.

Scorecard2 real differences Β· 4 level
RelativityTheory versus Simple Orbit Simulator: the parameters behind the verdict, then further details
ParameterRelativityTheorySimple Orbit Simulator
Price$0.99$0.99
Update frequencyEvery 3 weeksEvery 3 days β€” better
AdsNoNo
In-app purchasesNoNo
DevicesiPhone, iPad, iPod β€” betteriPhone, iPad
Requires iOS14.4 β€” better18.2
Further details β€” not scored
Size6 MB9 MB
Age rating4+4+
DeveloperTakao AkatsuBratislav Ljubisic

In-app purchases

None

RelativityTheory

No in-app purchases

None

Simple Orbit Simulator

No in-app purchases

Questions

Is RelativityTheory free?
RelativityTheory costs $0.99, with no in-app purchases.
Is Simple Orbit Simulator free?
Simple Orbit Simulator costs $0.99, with no in-app purchases.
Do RelativityTheory or Simple Orbit Simulator have ads?
Neither RelativityTheory nor Simple Orbit Simulator shows ads.
Which is updated more often, RelativityTheory or Simple Orbit Simulator?
RelativityTheory ships an update every 3 weeks, and Simple Orbit Simulator every 3 days. Most recently, RelativityTheory was updated on September 13, 2026 and Simple Orbit Simulator on September 7, 2026.

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