Itead’s Iteadlib Arduino Nextion Library is available
via github and can be downloaded from
https://github.com/itead/ITEADLIB_Arduino_Nextion

Default configuration is for the Arduino MEGA 2560
The Arduino UNO is also supported – see readme.md file
This framework concept can be used to port to another MCU

Newer components and Intelligent Series support has not been added.
However, most components can “borrow” from another existing component
and then be extended to suit your needs.