They're not unfortunately, but the Scribd app also doesn't work on the e-ink readers either (Scribd is really the only reason I have a Fire over e-ink). Lately my Fire has been having issues, so I'll likely switch over to e-ink next time I purchase one and give it a shot. But I think it's just something about physically holding a book that helps me retain more from it -- I've found this to be true even when I'm reading the same book on both (taking the Kindle out walking on a windy day, but reading the physical copy at home)