The plugin allows to easily visualize FlockLab Tracing Results and works together with Cooja, which is part of the Contiki Project. Download the Cooja FlockLab Plugin and extract the zip file into contiki/tools/cooja/apps. Open Cooja and install the new plugin via Settings > Cooja Extensions. You should then be able to access the plugin via Tools > FlockLab Visualizer.
In the serial output window, you can select a line and press space to jump to the position in the GPIO tracing where the output was generated.
If the plugin crashes on your machine, try to run Cooja with more memory: ant run_bigmem