Many technological applications (apps) purport to help children learn academic material. Building on research in developmental and educational psychology, we developed and tested an app to teach biological and physical science content to preschool children. There were 21 children in the control condition (M[subscript age] = 50.30 months, SD = 8.61) and 21 children in the intervention condition (M[subscript age] = 53.21 months old, SD = 6.36). Children were given pre- assessments and post-assessments of their understanding of living things, inheritance, buoyancy, and balance. Half were assigned to play the app for 3 weeks or to a control condition that only completed the assessments. Based on ANCOVA and ANOVA models, children in the app condition increased in their understanding of living things and buoyancy on a near-transfer task from pre-test to post-test assessment, whereas the children in the control condition did not increase their understanding. The findings suggest that drill and tests apps focusing on science content that take account of folk theories of science can support children's science learning.