GetThermal is a cross-platform thermal camera viewer application. This program makes it easy to connect a PureThermal 1 with FLIR Lepton or FLIR Boson to a computer running Mac OS or Linux, including the Raspberry Pi.
Binaries are available for desktop Linux (x64) and Mac OS platforms; see the Releases tab on GitHub. The Wiki tab has instructions for building on Raspbian. Success has also been reported on NVIDIA Linux for Tegra. Ultimately, any platform that runs QT 5.7+ and libusb should function with some effort.
GetThermal supports all FLIR Lepton variants used with the USB PureThermal 1 Smart I/O Module, including the Radiometric Lepton 2.5
Preliminary support for FLIR Boson has been added and is under development.