Wearable devices (e.g., smartphones, smartwatches, etc.) are increasingly used for position estimation of users both in indoor environments to provide personalized contents (e.g., malls, museums, crowded venues, etc.) and outdoor environments to provide additional information about their way of moving. Existing mainly solutions exploit the use of GPS which can provide very accurate location information in outdoor environments, while in indoor environments due to a variety of physical barriers that can attenuate the GPS signal (e.g., walls, floors) the quality of the provided information can be very poor. Other approaches which consist in the use of Wi-Fi, Bluetooth, barometers, and light sensors have been investigated and presented in the literature.