Context and motivation. Guaranteeing effective software requirement communication among stakeholders and software developers is crucial to ensure stakeholders’ satisfaction. Nevertheless, communicating software requirements is error-prone due to misunderstandings between stakeholders and software developers, producing misalignment between the expected solution and the final product. Problem. Some authors have proposed software requirements patterns to effectively specify requirements, relying on a reusable experience-based approach. However, industry studies show that using requirements patterns is not yet an established practice due to the lack of tools and scalability of existing solutions. Solution. This tool & demonstration paper presents the first version of the architecture of LEMON, a software requirements tool to assist requirements specification based on reusable and documented requirements patterns. In this paper, we exemplify LEMON’s components and present a tool prototype through a use case demonstration in the context of digital health software development. Results and conclusions. We conclude our paper by reflecting on the challenges, opportunities, and next research efforts towards maximising LEMON’s industrial adoption based on practitioners’ feedback gathered through an online survey