introspect
How do you spend your time?
This is very early days, but introspect can now successfully log OS X active window. It polls every second.
Quickstart
pip install introspect introspect_logger
Log File Location
introspect_logger writes to ~/.introspect. A new log file is written to every hour. The format is: "~/.introspect/introspect_YYYY_MM_DD_HH.log"