Kiwix

Read Wikipedia offline

Screenshots

Hunter's comment

Kiwix is a Wikipedia that enables you to run it even its offline, it can be really helpful usages for teachers and doctors having a mission where the place cant reach internet connection,

It is a modifiable free software so you can easily done modification on this software.

it has a full text engine feature that enables it user to find the things that he want accurately, it will give a lot of examples of the research.
It has an offline bookmark and note feature that will help its user to save where he stops and continue the work/research in another day.
Translated into more than 100 languages, very useful for teachers and student that are having a hard time with internet connection in their place.
Working on Android phones, F-Droid, Windows, Mac, and Linux OS.