Problem-solving ability is one of the abilities that must be possessed by students in the 21st century. Field studies obtain data that some students have low problem-solving abilities. This study aims to determine the feasibility of learning, improvement of problem-solving abilities, and differences in problem-solving abilities of students between classes using Android-based pocketbook learning media with classes that do not use Android-based pocketbook learning media on optical instrument concept. The method used in the study was a quasi-experiment with the design of a non-equivalent control group. The sample was selected using a purposive sample technique. The results showed that the implementation of learning was classified as a good category and there were differences in the problem-solving abilities of the two classes of students because the N-gain experimental class was 0.63 and the control class was 0.53. This shows that Android-based pocketbook learning media can improve students' problem-solving abilities in the optical instrument concept.