I got around and fixed the Windows specific issue as Philipp pointed out. I also had to take into account the File.lineEnding in order to make sure the parsing works on OSX and Windows.
If you haven’t yet, first download the Adobe Integrated Runtime (AIR)
Then download: RailsLogVisualizer0.6.air
After the log file is loaded the parsing takes some time and the UI doesn’t yet provide feedback for the progress. See be a little patient.
Please let me know how the RailsLogVisualizer works for you!