Quote from SAimNE
Oh and I almost forgot to mention it works as an offline reader as well... kinda important cuz that's what you wanted to start with xD. There is also one offline only called perfect viewer, but I've yet to try it with webcomics so no promises
Perfect Viewer is really the best for reading manga in android. It supports rar and zip support along with other features,and well its reader is more better than even Mango. It can match the height or the width depending on user input. So yes its best for both manga and longstrip webcomics. There is also an app called MangaWatcher. Its a paid product but its cheap. I rarely use it now as I prefer PC.
I think the thread OP is looking for computer related software.
You can try Honey View.(Credits~Eminorel).
Not sure if its perfect.
(Edit: Didnt noticed it was already mentioned)