Air sensors for everyone, everywhere! Air quality concerns all of us. The last few years we have been aware that indoor air quality strongly affects our cognitive performance as well as our health. Also, it is well known that outdoor air quality affects our health. Optical Non-Dispersive Infra-Red (NDIR) gas sensors are known to be the reliable and maintenance free alternative for air quality monitoring, but today they are too large and expensive for true mass-implementation. The route to turn the existing NDIR technology into IoT applications includes MOEMS technology using the evanescent field of chip-integrated folded waveguides too sense gas. It also includes 2D-materials, such as graphene, to be integrated on the chip for infra-red light detection as well as machine learning algorithms and geo-tagging for truly maintenance free operation. At the end of the tunnel we see air quality sensors that can be integrated in smart devices such as watches and phones, that will provide real-time data with high spatial resolution. Available for everyone, everywhere. Outdoor air quality in Stockholm measured using geo-tagging and a low-cost NDIR sensor.