ImageKit.io - Instant multi-platform image optimization
HakuNeko - HakuNeko is an all-in-one cross-platform utility that supports you to download manga and anime with various website support.
Resizing.app - Image resizing has never been so simple with free online resizing.app. Convert, optimize, resize images with ease and for absolutely free.
Free Manga Downloader (Unofficial Build) - Forked from https://sf.net/p/fmd/. Contribute to riderkick/FMD development by creating an account on GitHub.
Piio - Generates responsive images so you don't have to optimize
HDoujin Downloader - A powerful doujin/manga downloader that supports hundreds of different websites.