After Global Positioning System (GPS) came out, there was a need to improve its capabilities to work on indoor environments, because it revealed lack of accuracy when used inside buildings.

IPS systems are nowadays a big topic of discussion, because of its usability and potential due to the increasing number of smartphones all over the world. Smartphone built-in sensors are relevant to this application, because of their ability to implement
big part of the techniques described in the document.

The current existing android apps leave some space to improvements either on user experience or position estimation. The proposed solution combines readings from multiple sensors built-in the smartphone, attempting to create
a more accurate position and tracking Android application.