Reading books off a screen is kind of weird to me as well, and reading manga is even weirder, but I settled for it. I'm not positive where it stands now since I didn't see watermarks on yesterday's chapter, but in the past there was a manga website which reportedly had it for free legally! I can't... find it anywhere, though. I didn't plan on reading the manga originally either, but as you've probably heard, the anime is more of an exposition than anything else. It goes way deeper.