As mobile technology becomes more frequently used in science learning, understanding the relationship between student outcomes and the technology's pedagogical features is drawing increasing attention. This study focuses on one pedagogical feature--"who led the use." We first categorized 15 specific uses of mobile technology into three categories: student-led (i.e., initiated by the students and teachers have no or minimal influence on their use), teacher-led (i.e., initiated by teachers and the students have no or minimal impact on their use), and collaborative functions (i.e., both students and teacher need to play active roles in the use of mobile technology). We recruited 803 high school students who used a one-to-one tablet for 5 months and examined their use frequency, the functions used, and their physics outcomes. Results indicate a significant difference in the use frequency among the three categories. The collaborative functions were used with the highest frequency, whereas the student-led functions were used least. However, the student-led functions had a more significant effect size than the collaborative functions to predict both students' physics achievement and physics interest, while teacher-led functions failed to predict either of these outcome variables.