Dyslexia is a specific learning difficulty that affects primary school students, which is difficult to tackle through traditional school learning due to limited resources. To this end, large-scale digital learning presents new opportunities to address the need for inclusive education. A unique challenge for students with dyslexia in Hong Kong is learning Chinese characters. In this article, we investigate whether students with dyslexia can learn the writing of Chinese characters independently in an informal learning environment. For that purpose, we developed a mobile application for learning to write Chinese characters with three different writing conditions. First, students learn new Chinese characters in Condition 1: Grid+Contour+Instruction. Then, students strengthen their memory of the learned Chinese characters in Condition 2: Grid+Contour. Finally, students retrieve the memory of the learned Chinese characters in Condition 3: Grid Only. Students with dyslexia demonstrated a significant improvement after practicing with the three-condition design. For example, they wrote much slower than students without dyslexia before the study but caught up over time. This study contributes an approach to facilitate the self-paced learning of students with dyslexia at scale.