Greasy Fork is available in English.
Import and export bookmakrs from Mangakakalot, Manganato, Nataomanga, Nelomanga (id, name and visited number) to a txt or csv file on "Export Bookmarks"/"Import Bookmarks" button click
< Feedback on Mananelo/Mangakakalot/Manganato/Manga4life Bookmarks Export
Works well. Great especially if you have lots of bookmarks.