Several smartphone applications provide access to the measurements made by the sensors. We used phyphox, which is a free and open source software, very complete, available for android and iOS. This application is developed by the University of Aachen; we provided the French translation.
Fizziq is another application that can access smartphone’s sensors. It was developped in collaboration with the Main à la pate foundation, is free and require no registration. More info on fizziq.org.
The audacity software is usefull for processing audio files on a computer. It is a free and open source software.
Other sheets to do physics with smartphone and Arduino can be found on the site opentp.fr