More recently, the CMOS devices in pervasive smartphone cameras have been proposed as a practical distributed network to detect air showers from ultra-high-energy cosmic rays. The first app to exploit this proposition was the CRAYFIS (Cosmic RAYs Found in Smartphones) experiment. In 2017, the CREDO (Cosmic-Ray Extremely Distributed Observatory) Collaboration released the first version of its completely open source app for Android devices. Since then the collaboration has attracted the interest and support of many scientific institutions, educational institutions, and members of the public around the world. Future research has to show in what aspects this new technique can compete with dedicated EAS arrays.