In this paper I present and discuss our efforts and experiences with regard to those aspects connected to the design and implementation of seamless learning activities and how to promote those in order to become sustainable. A particular case in the field of mathematics education is presented and discussed. In terms of technologies to support seamless learning we promote the use of web-based, mobile tools and reusable and flexible components, as they allow teachers and students to create, adopt and adapt learning activities that connect the physical and the digital world across different locations and settings.