The design and implementation of hybrid, technology-enhanced learning environments is a sophisticated process, especially when incorporating relevant sociocultural factors to support culturally and linguistically diverse students' learning. In this paper, I review and provide a description of an iterative design process for a mobile-assisted funds-of-knowledge (FoK)-featured instructional framework that aims to facilitate middle-school aged Latinx English Learners' (ELs) literacy development in writing. The sociocultural lens of FoK considers ELs' ordinary experiences as assets in creating inclusivity and engaging flow in learning, which are further enhanced by affordances of mobile-based writing applications. More specifically, this design process was achieved through fieldwork situated in a Latinx community and school district in a rural town in the Midwestern United States. The design process was contextualized into four stages: the "precedent" stage focusing on the formation of the design idea, the "framing" stage focusing on the preliminary design outline, the "co-evolution" stage focusing on the development of the designed product, and the "prototype" stage focusing on experimenting with the designed product through the ELs' classroom writing practice. This instructional framework emphasizes the transformation of diverse ELs' ordinary experiences by guiding them through five sequential learning steps: "discovering," "connecting," "writing," "sharing," and "preserving" culture. Formative and summative evaluation techniques were embedded through different research phases, such as a preliminary instrumental case study, an ethnographic case study, and the ELs' classroom writing practice. This design case provides an example of socioculturally contextualizing the application of emerging technology to mediate learning for diverse student populations.