iBunkoHD 17+

Great app. The interface is simply beautiful although it's completely in Japanese. I do read Japanese but this would be a serious problem for Non-Japanese speakers especially when it comes to settings.
It has almost everything that Goodreader, Cloud Reader or iBooks are missing.

What I especially like about this app:
1. Built-in dictionary (Yahoo!辞書, 大辞林, Wiki etc). Not sure how useful this is for other people though since they are mostly in Japanese. But very neat function for Japanese speakers.
2. You can set up multiple bookshelves(本棚) on your own (It's different from Folders. The app supports folders too)
3. You can customize bookcovers with pictures from Photo Album
4. IT DOES SUPPORT .ZIP files (The developer did not specify in the description...)

What could have been better:
1. PDF does crash quite often.
2. Adding books to bookshelves from folders could have been more intuitive. Cannot add multiple files at one time.
3. Again please add English interface - this is such a great app. It's a shame if the language becomes a barrier.

This is the only app I’ve found that can handle manga PDFs with right-side binding properly. But the minimal UI and nice two-page spread support make it great for American comics too. Switching from GoodReader, for comics at least.

Here are my main grievances with the app as of May 2021: 1. It CANNOT be used in Split View on the iPad Pro in any way. Want to have a dedicated Dictionary app on 1/4 of the screen while iBunkoHD takes the other 3/4 of the screen? Too bad, iBunkoHD will simply cut off 1/4 of the pages you are trying to read. 2. No touchpad support: if you use the Magic Keyboard and want to use the trackpad cursor to select a word or sentence - too bad, the only thing it can do is to flip the pages, you have to use your figure to touch the screen to select anything. 3. No “Copy” option in the context (long press/double click) menu: this one is the absolute worst for any language learner. If you have a word highlighted, you can’t just choose a “Copy” open so you can paste it into another dictionary app. Oh no, you have to click “more option” (forget exactly how it’s called), and then a slow and unresponsive pop-up appears covering the entire screen, and in the center you can find “copy” among some of the other options. If you click it, it’s as if nothing happened, and maybe the word is copied after a few seconds., I could have forgiven all the other misses, but I do not understand the (lack of) logic of a text reader making it so tedious to just copy a word. It is very obvious that, despite calling this an “HD” version that cost extra, the developer spent minimal efforts and just took the the iPhone version and increased the resolution (and deliberately make the iPhone version not work on the big screen) and hasn’t been keeping this app updated to the latest iPad models and iPadOS firmware. It should not be charging money at the current state but rather taken off the store until it has been improved.

And I just checked the update history, besides bug fixes it hasn’t received a major update or overhaul in years. I have resigned to having wasted my money. Do not make the same mistake I did.