A way to mark a chapter as read.

[MarkJeronimus]

I request a way to mark a chapter as 'read' when it has been fully read (there has been a click on the last page that caused it to load the next chapter.

This by itself wouldn't be useful. One thing that's obvious is to show an overlay icon (perhaps a green checkmark) at the corner of a chapter folder. An alternative could be to make the chapter transparent, so it's obvious with a glance at a folder which chapters in that folder are 'read' and which aren't.

Furthermore, to make this flag actually useful when dealing with huge libraries of manga, is to allow the user to filter or sort by the 'read' status. A toolbar button could be used to show/hide 'read' manga. I'm not sure there's a way to implement a 'sort' feature that's both easy to use and doesn't confuse the user, but I could be wrong there. (I'm a backend developer, not a UX designer)