Grapheal adresses unmet needs in chemical sensing, and analytical testing, ranging from process monitoring to in vitro diagnostics, with unprecedented sensitivity, cost and speed. it relies on a technological platform based on a network of digital biosensors based on Field Effect Transistors (GFET) that can be read by a simple smartphone. Our GFET sensor platform is based on a proprietary graphene/polymer film compatible with printed electronics. Combined with bespoke surface functionalization, they enable real-time detection and direct quantization of a wide range of compounds with a simple smartphone. Our devices exhibit high sensitivity and selectivity, consume extremely low power (nanowatts), and deliver easily measurable signals, making them compatible with edge infrastructures.