DroidSense is an app that uses a Kalman filterto combine the sensors on an Android device with a mathematicalmodel of rigid body rotation and translation to provide acontinually updated estimate of the device's orientation andposition. The data can be logged to a CSV file and stored on thedevice.

Tumble is a tool for simulating therotationalmotion of a rigid body using user-specified parameters.The usercreates a database of rigid body models based on moments ofinertiaand specifies initial conditions for each. The orientationisrepresented as a quaternion and the angular velocity isexpressedin radians per second. The user also specifies torquefunctionsthat can be applied to each rigid body during thesimulation. Thesecan be expressed in terms of time, angularvelocity components,random numbers, and/or constants.Finally, the user matches up a rigid body model with atorquefunction and runs the simulation. The program draws acubeapproximating the shape of the rigid body based on thegivenmoments of inertia and uses it to visualize the motion. Duringthesimulation, a panel displays all the state information as wellas abutton that allows the user to pause and resume thesimulation.

Cycles is intended as an educational toolforlearning how ideal thermodynamic power cycles work. Itcurrentlysupports the Carnot, Diesel, Otto, and open Braytoncycles. Itallows you to specify the parameters for each cycle, thenanimatesthe cycle while displaying state information.

This is a GPS app for minimalists. Itallowsyou to view your current location, store and navigate towaypoints,and that's about it. A few more features like the abilityto searchwaypoints might be added in the future, but the name saysit all.Simplicity is the goal.

An educational engineering tool thatsimulatesthe orbit of an object around the Earth using governingequationsderived using the Lagrangian method. The app includes anadjustablesimulation based on user-specified initial conditions andsixhistorical example orbits to simulate (International SpaceStation,Hubble Space Telescope, Sputnik, Explorer 1, Vostok,andMercury-Atlas 6).In addition, there is a learning section detailing thehandcalculations upon which the simulation is based. Thelearningsection starts by explaining to coordinate system used,then coverskinematics up to the velocity level. The velocity levelkinematicsare used to construct the Lagrangian function, which isused inLagrange's equation to yield the three governing equationsfor thesystem.