Sensors based on optically-pumped magnetometers allow the development of room-temperature, wearable imaging systems for biomagnetism detection due to their excellent sensitivity, with applications such as Magnetoencephalography and Brain-Computer Interfaces. The small size of sensors based on microfabricated vapor cell technology promises high spatial resolution. The high sensitivity also opens up the possibility to use OPM sensors in other applications such as Very Low Frequency communications and ultrasensitive microwave detection.