I am using ILI9341 based LCD display in one of my projects, utilizing Raspberry Pi Zero.
I was able to install it under system. Display is visible as /dev/fb1.
Now I am looking for some simple C library, which allow me to do some basic graphic operations (printing text, drawing lines and circles, displaying simple bitmaps). Simple menu system would also be nice. Basically - I am looking for something similar to popular Arduino graphic libraries, but designed to use /dev/fb1 as low level IO device.