This book will describe the development of an indoor geopointing application on the mobile operation system Android. Due to limited accuracy and reliability of the orientation sensor, the work will introduce several algorithms to improve the data stability and usability. The algorithms extend the basic orientation sensor provided by Android. The suggested improvement checks the input data for compass calibration problems, magnetic field interferences and smoothens the data as well. Finally, the text will show the enhancement with a user case study and validate the geopointing algorithm with an implementation of an artillery game.