ContextLogger2 (CL2) is a tool for smartphone data collection, created primarily with research purposes in mind. It can, for instance, be used in user studies for collecting and recording context information such as GPS and GSM cell ID readings, keypress times, application focus changes, etc. The software presently supports Symbian OS based phones, has a lot of the functionality in place, but is still under active development as a small HIIT internal project.
The solution is based on client software installed on a phone that (typically) runs on the background, unintrusively recording information about activities taking place on the phone. The implementation makes heavy use of event-driven programming, an SQLite database engine, and a Lua runtime. More specifically: each “sensor” runs independently as its own “active object”, reacting to system events; all persistent data (including any logged data) is managed with SQLite; and configurability of the system revolves around the lightweight dynamic language Lua.