Urgh Perfect Viewer is totally not perfect. I really really dislike how you can't make it automatically fit the image to your screen if the images change size. Was reading NHK and some images are taller some are wider, etc. and so I basically had to tap the top left and right corners for every page to make sure it scaled properly.
turn those two into area for changing page, and set in setting "fit to screen" that will solve the problem, and actually make it a great app for manga reading
Here is what I do, and did
I had an iPad 2 for reading manga, but it was a horrible experience there aren't any good manga reading app for iOS, mangaStorm is you best bet, but even that one have a terrible UI. So I sold my Ipad bought a nexus 7, which lead me to this setup.
Mango - I use this for any ongoing manga, this is imo the best manga reading app on any platform. There is however one problem with it and that is missing support for reading archive files(zip rar 7z), which lead me to need one more manga app, which is perfect viewer.
Perfect viewer - it is quite a nice app, but it is far to complicated compared to mango. It has stuff like fit to width and fit to height, which are completely useless functions, since you want to use the setting "fit to screen", so you get to see the whole picture without scrolling. However when you have changed that area to just moving to the next page, it is actually a great app for reading manga, you get from places like bakabt.
Using e-ink for reading manga is a much better experience for your eyes, and if you use something like mangle it is quite easy to make it work perfectly(and it will flip all those 2side pages), however there are some problem. 1 it is a lot of trouble to manage you manga on your kindle, since it don't have much space, and you don't have automatic sync for it, so you need to move them over manually. The other problem I have is with the screen resolution, on the 4th generation kindle the text can be quite difficult to read when it is very small, this shouldn't be a problem with the paperwhite one since its higher PPI, but it is quite time consuming to get manga working on it. This has lead me to use tablet for reading even thought e-ink is much nicer to read on. Something like a nook with the google play on it would probably be the best solution, but nook have the same PPI as the 4th generation kindle, so there will be times where you can't read the text in manga without zooming.
@sawakosadako
he is using an android tablet, so that advise won't help at all