Book excerpt: As technology becomes more available to the general public, it is important that it be as accessible as possible. Accessibility for mobile apps is crucial given how pervasive smartphone use has become. For students who use MIT App Inventor -- an online platform that enables users to make their own mobile apps -- part of being an effective app designer is to appreciate the importance and practice of inclusive design. I have empowered young students to make their apps more visually accessible by: (1) offering new options for larger text, higher contrast, and alternate text in App Inventor apps, (2) creating a curriculum for students aged 13-18 about the principles of visually accessible design, and (3) running the workshop three times and collecting student feedback on the curriculum. After the workshop, students reported a more accurate understanding of the nature of low vision as well as increased comfort with making visually accessible apps. Overall, this work has shown that it is both simple and effective to teach the principles of accessible design to students as young as middle-school age. The code changes have been added to MIT App Inventor and the curriculum is available on the App Inventor website.