Mihon - Free and open source manga reader for Android
HakuNeko - HakuNeko is an all-in-one cross-platform utility that supports you to download manga and anime with various website support.
Aniyomi - Aniyomi is an unofficial fork of the free and open source manga reader Tachiyomi that adds anime capabilities!
Hitomi Downloader - Desktop application to download images/videos/music/text from Hitomi.la and other sites, and more.
Miru Project - A versatile application that is free, open-source, and supports extension sources for videos, comics, and novels, available on Android, Windows, and Web platforms.
HDoujin Downloader - A powerful doujin/manga downloader that supports hundreds of different websites.