The aims of this study are: (1) to develop iPad-based computer simulations called iSimPhysics that can help people learn Newtonian physics concepts; and (2) to assess its educational benefits and pedagogical usefulness. To facilitate learning, iSimPhysics visualizes abstract physics concepts, and allows for conducting a series of computer simulations implementing inquiry cycle and model progression approaches. To promote learners' motivation, iSimPhysics adopts various game mechanics in its learning tasks. To assess educational benefits and usefulness of iSimPhysics, selected questions from Force Concept Inventory (FCI) and Pedagogically Meaningful Learning Questionnaire (PMLQ) were administered before and after 17 graduate students used iSimPhysics. Paired t-tests indicate that students were able to solve more FCI problems (p < 0.01, ES = 2.28) and to provide more correct explanations (p < 0.01, ES = 1.19) after using iSimPhysics. Students' responses to PMLQ questions indicate that inquiry-based learning activities in iSimPhysics were helpful for them to learn target Newtonian physics concepts. The findings of this study may suggest that iPad-based computer simulations providing appropriate instructional scaffolding (e.g., visualization, inquiry cycle and model progression) can be an effective learning tool for physics (and possibly other science) concepts