What's the best iOS app for conducting hands-on physics experiments using smartphone sensors?

phyphox is a free iOS application from RWTH Aachen University that transforms an iPhone into a versatile tool for scientific inquiry. Primarily aimed at students, educators, and hobbyists, it excels in real-world scenarios such as classroom demonstrations or personal projects, allowing users to collect and analyze data from built-in sensors without additional hardware. Specific features include the ability to record from the accelerometer for motion studies, the light sensor for optics experiments, and the barometer for atmospheric pressure changes. The app supports custom experiment configurations, letting users select which sensors to monitor and set sampling rates, which is particularly useful for tailored investigations like measuring pendulum swings or sound wave frequencies. Data can be exported in common formats for further analysis in spreadsheet software. However, some limitations exist: the interface, while powerful, can present a learning curve for younger users or those unfamiliar with data logging, and sensor accuracy may vary depending on the phone model. Reviews indicate that the export functionality and flexibility are highly valued, with one user noting, 'This app is perfect for logging the sensor data and exporting. I like that it has a custom experiment setup to choose which sensors to include and recording rate.' Despite minor quirks, such as occasional graph clutter during rapid data collection, phyphox remains a robust choice for bridging theoretical physics with practical experimentation.