I've uploaded new versions of the program with two improvements. I've added icons to the global configuration menu to make the text larger and more readable. I've also added a cartoon panel detection and navigation feature. It can automatically detect the location of panels, and then the arrow keys can be used to jump between the various panels on each page, centering on each one. It probably isn't as useful as using a stylus to drag the image, but for those of us without touchscreens, it should make reading cartoons and manga easier.
You can enable it on a page-by-page basis by doing a long press on the Left or Right buttons. Pressing the Right button orders the panels from left to right, and pressing the Left button orders them from right to left. You can also toggle automatic panel detection in the main menu, so that you can start navigating immediately as soon as each new page appears. The Back button cancels panel navigation on that page if you want to go back to normal navigation. The Left and Right buttons jump consecutively through the images, changing pages when you go past the first/last panels. The Up and Down buttons can also be used to move to panels immediately above and below the current panel.
The panel detection only works if the panels are completely separated from each other with background space between them. Any line connecting separate panels results in them being treated as one panel. The current panel has a black rectangle drawn around it to make it easier to understand what is going on during navigation, especially when multiple panels are grouped together. The background between the panels is assumed to be White by default. If it is Light Gray or Gray instead, you can specify that from the menu to improve panel detection.
The detection algorithm is usually pretty fast, but starts to slow down as the images get very large. The settings are not saved when the program quits, so you have to re-enable it whenever you open the file again.