Booru - https://github.com/Bionus/imgbrd-grabber
Tumblr - https://github.com/bbolli/tumblr-utils
Reddit - https://github.com/shadowmoose/RedditDownloader
4chan - Koruba android app (see fdroid)
best friend 4ever: python + beautifulsoup4
to get:
-website archiver (just static ones) [python-wget script?]