Treballs Finals de Grau d'Enginyeria Informàtica, Facultat de Matemàtiques, Universitat de Barcelona, Any: 2017, Director: Sergio Sayago BarrantesFinding a lost object can sometimes be a very tedious task. Moreover, no matter how hard you try to find that object, you might not be able to find it. Consequently, people tend to give up looking for lost objects. To make matter worse, when someone finds a lost object and has the intention to give it back to its owner, s/he does not know how to do it. This TFG does not aim to provide 'the' solution to this problem, as doing so rests upon a lot of research. Instead, this TFG aims to help to keep the owner of a lost object in touch with the person who found it through an app wherein found or lost objects registered, by introducing their physical features, when they were found and where. In order to find the lost object, it is mandatory that both the owner of the lost object and the person who found it register the object in the same way. If there is a match, the application will notify both users. Upon a confirmation, both the owner of the object and the person who found it agree on how, when and where they can meet. This 'negotiation' is not carried out through the app. In order to carry out this project and develop the app, we reviewed previous works and conducted semistructured interviews with end-users to gather requirements. Once all the functionalities where narrowed, having in mind the regulation of the Civil Code that regulates lost objects in Spain, we developed the database, client and server side of the app. The client side was developed as an application for Android devices, developing the main functionalities that allow the users to register lost and found objects. The server side was implemented with a web server apache that contains the matching algorithm that matches lost and found items, and the database that contains all the information related to the users and objects.