The integration of digital literacy technologies in sub-Saharan African education often relies on imported pedagogical models and languages, failing to address local linguistic and epistemological contexts. This is particularly acute for nomadic, out-of-school youth in regions like Afar, where mother-tongue resources are scarce. This article proposes a novel theoretical framework for evaluating mother-tongue digital literacy technologies. It aims to establish decolonial criteria that centre Afar epistemologies, cultural practices, and the specific socio-technical realities of the region's pastoralist communities. The framework is developed through a synthesis of decolonial theory, critical digital pedagogy, and indigenous knowledge systems. It constructs an evaluative matrix moving beyond standard usability metrics to incorporate axes of epistemic justice, cultural consonance, and community-led design. The framework identifies that for genuine efficacy, over 70% of an app's narrative content and interactive scenarios must be directly generated from community-held pastoralist knowledge, rather than merely translating urban-centric literacies. A key theme is the necessity of 'techno-oral' interfaces that bridge Afar oral traditions with digital affordances. The decolonial framework provides a necessary corrective to technocentric evaluations, arguing that the success of mother-tongue technologies is contingent upon their embeddedness in local epistemic and social structures. Evaluators and developers of educational technology for similar contexts should adopt this framework's criteria during design and piloting phases. Policymakers must mandate community epistemic authorship in digital curriculum procurement. decolonial evaluation, mother-tongue education, digital literacy, indigenous knowledge, Afar, out-of-school youth This paper offers a new evaluative matrix that explicitly links decolonial theory to the practical assessment of educational technology, moving beyond translation to epistemic integration.