I have a GLK24064-25 and could not find an arduino library to use the LCD over i2c.
My guess is that the price tag deters most people.
Anyway, here is the library: https://github.com/nherment/Arduino-Library
It's not a complete library but it's what I needed. Also, please excuse my noob's C++ skills (I come from a Java background so I'm not totally excusable...)
Here is a video of the LCD in action showing the charting capabilities using the Chart class:
The Chart handles the range automatically and can switch between 3 modes. Regular bar chart, Reference based bar chart (when bars go up and down from a reference line) and Line chart.