Despite the recent advances in mobile tourism systems, most of the wayfinding applications have still to deal with some problems: a huge amount of tourist information to manage, guidance for indoor and outdoor environments, and the need of users to have programming knowledge about many mobile phone platforms. In this study, we propose the GAT platform to overcome these problems. In GAT, users are able to generate wayfinding applications for indoor and outdoor environments through a web form without the need for programming skills, assisted by a system of automatic generation and update of points of interest