Hi all,
Based on the other script by Redboyrave (thanks for sharing! <3) I made my own that is different like this:
Just make an image in Aseprite which size is a multiple of 16x16 and the script will export the 16x16 zones as individual sprites in GBDK compatible .c/.h
This is mainly because I want to make many monster sprites in one Aseprite file, and maybe because I don’t know the right way to do it 
Anyway it works and if it helps you, I’m happy : https://github.com/AlanFromJapan/gbdk-sprite-exporter