4chan is a simple application written in go that tries to download
all images from some 4chan board.
If you want to change the board, just change the /g/ to /a/ or
whatever.
If the board is a red board, then don't forget to change
https://boards.4channel.org/ to https://boards.4chan.org.
It will download all the images in ~/4chan folder. Some images can be corrupted.