Some usability tweaks for a few manga sites.
This doesn't fundamentally change the UX like https://greasyfork.org/en/scripts/1319-manga-onlineviewer would.
It just enhances a few things.
Ads are generally gone. SEO nonsense is mostly hidden. Comments and related series are collapsed by default.
You can use keyboard navigation: ← / → or A / D to navigate between chapters.
Chapter images are fully loaded, and the next chapter images are prefetched.
The last chapter read is tracked, and a badge is added on series showing how many unread chapters are left, in bookmarks and on a few other pages.
You can drag around to scroll with your mouse.
On desktop, you can drag horizontally until you see a double arrow to navigate between chapters.
On mobile, you can swipe left and right to navigate between chapters.
You can press K / L to rotate pages by 90°, so you no longer have to flip your monitor sideways to enjoy those bits.
Press F to toggle full-screen mode.
(Swiping to navigate doesn't work in landscape mode, that motion is better used for scrolling the strip, and swiping up/down makes little sense.)