Komikku is described as 'An online/offline manga reader for GNOME, developed with the aim of being used with the Librem 5 phone'. There are more than 25 alternatives to Komikku for a variety of platforms, including Android, Windows, iPhone, iPad and Android Tablet. The best alternative is calibre, which is both free and Open Source. Other great apps like Komikku are Amazon Kindle (Free), FBReader (Freemium), Tachiyomi (Free, Open Source) and Moon+ Reader (Freemium).
Calibre is a free and open source e-book library management application made by users, for users. Many languages, designed around the concept of the logical book, i.e., a single entry in your library that may correspond to actual e-book files in several formats.
Amazon Kindle software lets you read ebooks on your Kindle, iPhone, iPad, PC, Mac, BlackBerry, and Android-based device. You can discover and read over 630,000 books in the Kindle Store, including the latest bestsellers and new releases.
Innovative book reader with powerful controls & full functions: • Read thousands of ebooks for free, supports online ebook libraries • Read local books with smooth scroll and tons of innovation Support epub, pdf, mobi, chm, cbr, cbz, umd, fb2, txt, html, rar, zip or...
Google Play Books lets you search, preview, and buy millions of books using Google Book Search. Books in the public domain and certain copyrighted books can be read and downloaded in their entirety for free.
YACReader (Yet Another Comic Reader) is a free cross-platform comic reader with support for multiple comic files and image formats. YACReader comes with YACReaderLibrary an application for browsing and managing your comic collections with various smooth transition effects.