LibreCGM is a program for optically reading the daily graphs on the FreeStyle Libre Continuous Glucose Monitoring device by Abbott to obtain the values on systems not supported by the official drivers and software.
The values can be saved as either plain blood sugar values with timestamps or rendered to (yet another) graph.
Additional features include:
Option to use mg/dL instead of mmol/L
Reading from image files or previously saved blood sugar values
Fully usable through the commandline interface
The algorithm to find the screen on the webcam/image relies on the device's screen being the brightest thing in view. This might mean it won't work in bright environments such as outdoors on a sunny day
Missing .desktop file for integration with graphical desktop environments (and an icon to go along with it. Art contributions welcome)
Lacking graceful fallback when libraries are not available, e.g. if the font libraries are missing it could still draw a numberless graph and save values (fixed in 2021.09.25-2da2264ab4ad67eb)