Kiwix is an offline wikipedia viewer. See the official site: https://kiwix.org/ You need to download an archive (ZIM file) from https://download.kiwix.org/zim/, store it in on your device, and manually select it after starting the extension. You can search among the article titles, and read any of them without any Internet access. All the content of wikipedia is inside your device (including the images). It might also works with other content in the OpenZIM format: https://wiki.openzim.org/wiki/OpenZIM , but has been only tested on the wikipedia and stackexchange ones. If your Internet access is expensive/rare/slow/unreliable/watched/censored, you still can browse this amazing amount of knowledge and culture.