ENVI (Environment for Visualizing Images) is the gold standard for hyperspectral analysis. It reads virtually all spectral formats, including IS2.
This is described by its developer as an "experimental tool" with slightly inaccurate temperature values and is intended "only for study and demonstration purposes." The developers have also noted that while the .bmp and .jpg files created by the camera's own settings are ready to use immediately, they don't allow for full analysis or modification. It is not an official Fluke product, so use it with caution. is2 file to jpg converter
For users comfortable with technical tools, there are open-source utilities like the fluke-ti-tool available on ENVI (Environment for Visualizing Images) is the gold