Bug
I'm a big fan of Web Comics. When reading a comic from top-to-bottom, YACReader on iPhone often doesn't mark it as read because the last image is not registered being read although it is on the screen.
I believe the reading progress is registering the image being shown on the top corner of my iPhone.
Web Comics split a whole strip into standardized sizes and the left over at the bottom can be a fraction of a normal image.
Possible solution
For registering a web comic as read please add a condition such as
if is_last_image_being_shown = true
then
current_page = pages
read = yes
Attached I have provided an example to play with. Just rename it to cbz. 3 normal sized images and the 4th being the "left-over".
bug.zip