Why is your app asking for full internet access? It is not ad supported, and so far as I can tell has no reason to need this permission. What information is it getting/sending, and why?
The 2 other apps that have similar functionality to yours, JJ Comics Viewer and Perfect Viewer, don't require this permission. In fact the Perfect Viewer app doesn't need any special permissions at all.
I think your app looks nice, and would like to give it a try, but (unlike a lot of people out there, I am sure) I do like to know what it is doing with the permissions it gets at install.