Today, many of the location-based services (LBS) related to urban mobility rely on smartphones. The availability of raw GNSS measurements on Android phones has opened up the possibility of exchanging such measurements for improved accuracy, precision, robustness, and availability. Collaborative ranging and cooperative positioning (CP), if implemented with the smartphones’ ultra-low-cost GNSS chipsets, can enable a plethora of applications that support a modern smart city framework. Cooperative Android Positioning System for Localisation (CAPS-Loc) proposes developing an optimal framework on Android smartphones for the exchange and nearreal-time exploitation of raw GNSS measurements, as well as improved LBS. It is slated to provide three key functionalities: A network structure for the real-time exchange of measurements, one white box for the combination of measurements by means of time synchronisation, and a second white box for the integration of collaborative data into the main navigation algorithm. Aside from being a server-based system, CAPS-Loc is expected to use a phone-to-phone mode based on Wi-Fi direct to ensure continuity of its service when no network is available.