This chapter describes how the use of apps can foster learning literacy practices in different disciplines; learning described in terms of disciplinary literacies. By disciplinary literacies, one therefore means those particular literacy practices unique to certain disciplines as subcultures, domains, or communities that value certain ways of knowing and thinking. Students are continually acquiring uses of a range of different tools mediating their learning. The English Language Arts Common Core State Standards related to disciplinary texts and reading the text are posed as English language arts standards, not as social studies standards or science standards. Students also acquire disciplinary literacies using apps with the affordances that mediate their peer interactions as members of communities of practice, as they just noted, and of 'passionate affinity spaces'. Central to second language or English language learner (ELL) instruction are opportunities for students to practice use of language for a range of different communication purposes.