Geostationary Orbit 3D Lab app for iPhone and iPad

About
An open source physics at Singapore simulation based on codes written by Francisco Esquembre and Loo Kang WEE.
more resources can be found on support URL


Introduction
A geostationary (Earth) satellite is a satellite that rotates around Earth in a certain orbit such that it is always positioned above the same point on the Earth’s surface. Hence from the point of view of an observer standing at that point, the geostationary satellite appears to be always ‘stationary’ above him/her (but actually, both observer and satellite are rotating at the same angular speed). In order for a satellite to be moving in such a geostationary orbit, there are certain conditions to meet:

placed vertically above the equator
same directional sense as the rotation of the Earth (determine through axis of rotation)
same orbital period of Planet, in our case, Earth, thus the orbital period of approximately 24 hrs

The simulation has a Earth and a Satellite object Menu Drop Down Allows for selecting what motion of Satellite is simulated.
Geostationary near Singapore
Geostationary near Africa
Geostationary near America
Non-geostationary due to direction
circular motion r=3*Re, T =7.30 hr
circular motion r=10.5*Re, T = 48 hr
Non-Geostationary generally
Unlikely Orbits
Options added are:
Show:equator Plane, for visualising the Earths rotating equator plane
Geo stationary, for visualising a geostationary object (RED) for comparative observation with the other modes.
Show text: 35 700 km fixed position of object relative to planet earth.
Axes earth: show spin axes of the rotation of earth in GREEN
Axes satellite: show spin axes of the rotation of satellite in MAGENTA
Force: pair of action reaction force of equal magnitude, opposite direction and on different bodies. (Newtons 3rd Law)

Acknowledgement
My sincere gratitude for the tireless contributions of Francisco Esquembre, Fu-Kwun Hwang, Wolfgang Christian, Félix Jesús Garcia Clemente, Anne Cox, Andrew Duffy, Todd Timberlake and many more in the Open Source Physics community. I have designed much of the above based on their ideas and insights.
This research is supported by the eduLab project NRF2015-EDU001-EL021 , awarded by the Prime Minister Office, National Research Foundation (NRF), Singapore in collaboration with National Institute of Education (NIE), Singapore and the Ministry of Education (MOE), Singapore.