Promoting teacher innovation through Information and Communication Technologies (ICT) Teacher Professional Development (TPD) in low-resourced primary schools remains a persistent challenge, shaped by systemic inequalities and resource constraints. This paper explores how ICT-TPD programmes can foster innovation in such contexts, focusing on a case study of a low-resourced primary school in Johannesburg, South Africa. A mixed-methods design was employed, with data collected from six teachers who participated in a structured ICT-TPD programme aimed at strengthening curriculum integration. The findings reveal that while teachers were motivated to innovate, barriers such as unreliable or unavailable devices, limited internet connectivity, and high workloads constrained sustained adoption. Some teachers demonstrated agency by independently acquiring devices, while others struggled to maintain consistent engagement, underscoring the need for differentiated support. Grounded in the Diffusion of Innovation (DOI) framework, this study extends the model through a proposed DOI-plus, which incorporates contextual sustainability as a sixth attribute reflecting systemic and infrastructural conditions beyond individual control. The study argues that ICT-TPD must be context-sensitive, adaptable, and designed to provide ongoing support and opportunities for experimentation. Such approaches can enable teachers in low-resourced schools to overcome systemic barriers and embed innovative ICT use into their pedagogy.