The student's need for English wntmg materials that can improve the student's writing skills is to make the learning process more interesting, challenging, and interactive. This study aims to develop English writing materials model based on Smart Application Creator for junior high school students. The objectives of this study were : (I) To identify the students needs for English writing materials in junior high school, (2) To design the English writing materials based on SAC for junior high school, (3) To develop of English writing materials based on smart application creator for junior high school, (4) To implement of English writing materials based on smart application creator in grade IX, (5) To find the effectiveness of English writing materials models based on smart application creator for teaching the students. This research method uses the ADDIE model approach which has five steps. There are analyze, design, develop, implement, and evaluate.It determines the effectiveness of English writing materials based on SAC in the learning. This uses research and development ( R&D ) study. The subjects of the study were the students in the ninth grade of SMP Negeri 2 Tanjung Pura. It was conducted at SMP Negeri 2 Tanjung Pura. The instruments for collecting data were questionnaires, interview, and English test.This writing materials uses a contextual teaching and learning ( CTL ) approach to improve the student's writing skills. The final result show that the average result of content expert's score is 89%. The average result of media expert score is 87%. The average result of student's response score is 85,9 %. The average result of teacher response score is 88,3%. There are differences in test result before and after the developing English writing materials based on smart application creator. The average post-test is higher.There is a significant improvement in student's writing skills after they were taught using writing materials based on smart application creator. It can be concluded that developing English writing materials based on smart application creator is effective in increasing student's writing skills in learning.