G is a Gravitation simulator designed for iPad / iPhone.

Check the demo video at

G allows you to quickly experiment the effects of the Universal Gravitation by adding bodies into a simulation, seeing how they react to each other in real time, all in a true multitouch environment. G offers a vast universe to add your bodies into, potentially allowing you to create stable planetary systems, binary star systems, and other multiple-body complex systems.

G is very simple to use. When you first start it, you are presented with the solar system. The Sun and all planets from Mercury to Uranus are added to the simulation, including the Earth's Moon.

First, get familiar with how to navigate G's Universe.

- Drag on empty space to pan around the universe
- Pinch (two fingers) to zoom in and out the Universe.
- Tap on a body to select it, making the camera follow it.

You can then start interacting with the system, by adding new bodies, modifying or deleting the existing ones.

- Double-tap on empty space to create a body.
- Drag after double- tap to set the new body's initial velocity.
- Drag an existing body to relocate it.
- Double-tap on an existing body to set a new velocity.

The placement, the mass and the initial velocity of the newly added bodies will dictate how "successful" your system will be. Bodies in G will collide when in contact, so if one of your bodies hits another one, they will merge into a single body, creating debris in the process.

Want to see what would happen if our Sun suddenly disappeared? Just delete it from the simulation, and watch all the Solar System planets react to the change... What would happen if the sun decreased it's mass? Go ahead and try it, it's not pretty.

G provides a settings screen that allows to toggle various visual aids, (universe grid, body trails, etc), as well as the simulation speed.

G allows you to store your systems to get back to them later. Up to 7 systems can be stored simultaneously, and loaded anytime. A screenshot of the system is also stored together with the date it was stored in. G also provides a few presets, including the Solar System, and a few other particular systems. You can also import/export your systems from/to any other app (Dropbox, for example) or email.

The physics implemented in G follow "Newton's Laws of Universal Gravitation", which states that every massive particle in the universe attracts every other massive particle with a force which is proportional to the product of their masses and inversely proportional to the square of the distance between them.

In case you are curious about Newton's Laws of Universal Gravitation, G provides a quick view of the Wikipedia's definition of such laws.

What’s New

Version 2.10

Lots of new features!

True multitouch interface; pan & zoom while creating / moving, perform multiple actions at once.
Improved zoom
New body editor allows numerical data input
New body cloning tool
In-place dynamic mini-UI
File export, share your system by email, dropbox, etc.
User action panels, indicate which action each finger is doing + numerical data.
New adaptive space grid, covers all user space, less intrusive
User selectable simulation precision
Body collisions now produce space debris
Improved body looks, LOD textures
New compass, always points to system's origin coordinates (0,0) when not on screen
Orbit previews when editing the system
Realtime gravitational field preview when editing the system
Improved looks on prediction path
User Interface overhaul, left and right handed ready, customized native UI elements
Sound effects
Proper retina support
New factory presets, including "Binary Star", "Spirograph" and others
App analytics, can be disabled by the user
Countless small tweaks to make the app great

Ratings and Reviews

2.9 out of 5
7 Ratings

7 Ratings

doodier ,

Wiki link is down

Tab to Newton's Laws of Gravity returns error

Infinitize Studios ,

Super Fun

I think you should add black holes because that would make it so much fun! But the app is still great without!

Marc Country ,

Good Planetary Orbit Simulation App!

This app fulfills its main function well, which is to simulate the gravitational orbits and attractions of bodies in space. As other reviewers have noted, it could use some improvements.

My suggested improvements
-New Bodies Mass is controlled by a slider, but it should have a numerical input too, or at least show you the numerical value that you've selected with the slider.
-Trail Length should be variable for individual bodies. Earth, Venus, and Mercury can all draw their complete orbits with a trail, but Mars can't draw it's full circle even with the longest trail settings.
-It would be nice to be able customize the colours of the planets/stars/etc.
-It would be good if you could choose to label (or not) your bodies individually as well, so you can name several moons around a planet, but not have them all show up as a jumble of letters on top of one another when you zoom out. Instead, you could have the option to keep some labels on while others are off.
-some ability to output a saved file to a .jpg or some type of still image (or an animated gif, even!) format would be a fantastic addition to this app.
-it would be nice if all the moons for all the planets were in our solar system model, not just Earth's moon, and a Saturn with real orbiting rings would be an excellent finishing touch. It would be helpful if users had a planet model with working orbiting rings of tiny massed objects as a ready-made template to experiment with.
-lasting fragments from collisions would be good.
-apparent speed of orbits could increase as you zoom out.

Hopefully the developer can take these and other user suggestions on board to make a good orbital simulator app into the BEST orbital simulation app!

App Privacy

The developer, Oriol Ferrer Mesia, has not provided details about its privacy practices and handling of data to Apple.

No Details Provided

The developer will be required to provide privacy details when they submit their next app update.


Oriol Ferrer Mesia
7.9 MB

Requires iOS 5.0 or later. Compatible with iPhone, iPad and iPod touch.


English, Catalan, Czech, Danish, Dutch, Finnish, French, German, Greek, Hebrew, Hungarian, Italian, Japanese, Korean, Norwegian Bokmål, Polish, Portuguese, Romanian, Russian, Simplified Chinese, Slovak, Spanish, Swedish, Traditional Chinese, Turkish

Age Rating


  • Family Sharing

    Up to six family members will be able to use this app with Family Sharing enabled.

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