Pocketbook devices run Linux. Linking to an account or connecting to a network is entirely optional. I haven't done much with mine other than install koreader and read epub files copied over usb, and it's been perfectly adequate. I bought mine through goodereader and although it worked out I regretted it. I'd have been better off ordering it on aliexpress myself and retained the tracking and dispute options, rather than paying goodereader a premium for the same experience.