GPU Fan Meister can be downloaded from the official website: https://gpufanmeister.alkatrazstudio.net. At the moment there is a build only for Linux. Also, the systems on Wayland are not supported.
GPU Fan Meister is distributed in the AppImage format as a single executable file, but this file is not fully self-contained. In particular, the Python 3 interpreter and D-Bus must be installed to run the program on Linux. These programs are usually already pre-installed on Desktop Linux. Also, each of the plugins may have its own requirements to run. For example, the requirements for the nvidia-nvml plugin, which is included with GPU Fan Meister, are described on the corresponding page.
GPU Fan Meister is a free and open source project, so you can try to build it from source by following build instructions.
You can view the list of changes of GPU Fan Meister here: https://github.com/alkatrazstudio/gpu-fan-meister/blob/master/CHANGELOG.rst.