Planet Fun is a 4D solar system simulation for Android and iOS and it is built in Delphi. Planet positions are calculated using VSOP2013 ephemeris, years between 1500 and 3000 according the developer. The app is built using FireMonkey 3D functionality and full source code is available. Among its features are a solar system animation with configurable speed, choose camera target (Sun or planets), set date/time between years 1500 and 3000, configurable distance-to-target, touch gestures: one finger pan, two finger zoom, two finger rotation, planet orbit dots plus each orbit is represented by 52 dots (For the Earth, its one dot per week), heliocentric axis (x and z), VSOP2013 high res planet positions, moon position calculations, a star background with 42455 stars of the Hipparcos Input Catalogue, it uses phone sensors ( compass, gyro and GPS ) to control 3d phone attitude, and the phone in the scene is positioned with phone sensors (GPS, gyro and compass). This is a fun little app and shows a nice implementation of cross-platform Delphi FireMonkey 3d.