Using offline data on aquafish aka Jolla C

• Download heremaps for your country. 

• Install GCIDE Dictionary and FBreader from openrepos. You can get religious books like bible, english grammer, britannica encyclopedia in parts etc from gutenberg.org

GCIDE Dictionary

Install Zimpedia. Download and copy zim files from wiki.kiwix.org SD cards maynot support files larger than 4 GB depending on technology

Zimpedia

Using Zimpedia

So download simple english wikipedia wikipedia for schools, Wikipedia in your language etc. Medical wikipedia, Wiktionary, Wiktionary, Wikibooks, Wikiversity etc, depending on your need

Also try downloading NCERT books in epub format by serching on internet. You can read them on FBreader by putting under subfolder of FBreader. This will be very useful for students (http://www.gokuldeepak.com/download-ncert-books-epub-edition/)