The Malaysian Ministry of Education has stated that the main objective of education is to produce students who possess higher order thinking skills (HOTS). For this purpose, students’ engagement in teaching and learning is of great concern. In the initiatives taken to help them towards achieving a better level of thinking, teaching and learning resource is one of the important factors to be considered to effectively get them engaged in active learning. One of the resource alternatives that can be used is to integrate technology into teaching and learning. Mobile technology is one of the latest technologies which has the potential to be leveraged in realizing the intended objective. Thus, this paper discussed the ways, the development of Mobile Problem-Based Science Dictionary (DicScience PBL), was able to help students not only in mastering scientific terms but also helping them to think more critically. By combining constructivism design principle and problem based learning (PBL), the PBL processes and critical thinking elements in the development phase, this application was able to give positive effect to the students’ mastery in scientific terms (M=48.56, p