Digital technologies are promising tools for sustainable agriculture; however, the cutting-edge digital solutions in agriculture are impractical for smallholder farmers in developing countries. Smallholder farmers need access to credit and insurance services, quality farm inputs, advisory services, subsidies, and market services to be able participate in sustainable agriculture. This paper is part of an extensive study conducted using the design science research (DSR) methodology. As part of our previous research, we conducted a thorough survey of the various stakeholders in Tanzania to assess their needs. Thereafter, we designed a conceptual digital framework called Farmers’ Digital Information System (FDIS), which provides all the necessary services to smallholder farmers and other stakeholders and addresses the identified needs. This paper presents a technical implementation of FDIS that aims to deliver essential services to smallholder farmers for sustainable agriculture within a comprehensive single mobile application. We used Android Studio Iguana and a Flutter framework to develop four service modules that include farmer and farm data, advisory services, and financial and marketing services as part of the FDIS platform. The system reflects the services offered in a real-world environment, as farmers can directly request advice from experts, apply for credit services from financial institutions, and market farm products to meet potential customers. It solves problems of access to farm advisory services and credit services for farm investment and helps farmers to find reliable markets for their products without going through intermediaries (middlemen). The completion of the FDIS development presented here will be followed by a test of the platform with real users for evaluation and improvement. Future research will focus on the scalability of FDIS for different regions, the embedding of more advanced technologies, and the adaptability of FDIS to different agricultural ecosystems. The FDIS solution has the potential to improve sustainable farming and empower smallholder farmers in Tanzania and beyond.