This book constitutes the thoroughly refereed post-conference proceedings of the First International Conference, SENSAPPEAL 2009, held in Athens, Greece, in September 2009. The 12 revised full papers were carefully reviewed and selected from 24 submissions. The papers cover various topics such as WSN for fire hazard detection and monitoring, WSN for precision horticulture, a nephelometric turbidity system for monitoring residential drinking water quality, deployment of a wireless ultrasonic sensor array for psychological monitoring, WISEBED: an open large-scale wireless sensor network testbed, SmartEN: a Marie Curie research framework for WSN in smart management of the human environment, embedded web server for the AVR butterfly enabling immediate access to wireless sensor node readings, as well as TinySPOTComm: facilitating communication over IEEE 802.15.4 between Sun SPOTs and TinyOS-based motes.