This work presents a mobile application developed for Android devices that captures and records the data measured by the smartphone's built-in accelerometer. The app displays in real time the acceleration components along the three spatial axes (X, Y, Z), and also allows users to store the acceleration data over a configurable time interval in a plain text file for further analysis.

As an application of this tool in an educational context, we propose a laboratory experiment designed to help students understand the nature of circular motion, centripetal acceleration and the physical location of sensors inside modern smartphones. In the experiment, the smartphone is mounted on a robotic arm that rotates at a constant angular velocity, producing uniform circular motion. By analyzing the recorded accelerometer data and knowing the angular speed of the arm, students can calculate the magnitude of the centripetal acceleration experienced by the device. From this, they can estimate the radial distance from the center of rotation to the accelerometer’s actual location within the phone.

This practical activity encourages active learning, fosters students' critical thinking and data analysis skills, and bridges the gap between theoretical physics and real-world technology. Moreover, it introduces students to the use of everyday digital devices as scientific instruments, promoting low-cost experimentation in STEM education. The app is easy to use, requires no internet connection, and can be adapted for other experiments involving motion analysis.

The proposed activity has been tested with undergraduate students in physics and engineering courses, showing a high level of engagement and a better conceptual understanding of non-inertial frames, circular motion, and sensor technologies. This approach demonstrates how mobile technology can be integrated effectively into the physics lab to create meaningful, hands-on learning experiences.

Keywords: Accelerometer, laboratory experiment, physics education, remote learning, smartphone.