Multi-device activity logging

In this paper we are presenting i-Log, a system which is able to collect user's personal information, generate streams of data from smartphone's integrated sensors and attached wearable devices. We decided to focus our attention on these general purpose devices as we believe they can generate truthful readings because of their easy integration with our day-life activities, while invasive dedicated logging devices can alter our normal routines. The system consists of a Mobile Application that collects sensor data from the smartphone and from additional external wearable devices through a Bluetooth connection. We designed it to be user friendly, transparent, unobtrusive and able to provide smart sensing strategies in order to preserve battery life. More-over, i-Log has a back-end server that accepts streams of data from the application and stores them into a persistent storage system that can be queried for further real time analysis.