Do you feel very hard to remember some Linux command or their parameter?
Do you want to take advantage of commute time to read the document?
Are you tired of other document reading app which build with the heavy UI and ad. reading ?
Debian Doc is exactly your choice. It packs almost all the documents from official DVD iso images(https://www.debian.org/CD/torrent-cd) into the app. When searching or reading the doc it does not require any android permissions, supports full-text search, no ads, find in page, click on related documents to jump, bookmark. Those convenient functions allows you to read man doc more efficiently, quickly and intently.

Man doc including
man1 - Executable programs or shell commands
man2 - System calls (functions provided by the kernel)
man4 - Special files (usually found in /dev)
man5 - File formats and conventions eg /etc/passwd
man6 - Games
man7 - Miscellaneous (including macro packages and conventions)
man8 - System administration commands (usually only for root)
man9 - Kernel routines [Non standard]

Features
No permissions, even internet.
No ads.
All documents is offline.
Full text search.
Find in page.
Add bookmark.
Navigate between documents

Happy reading and don't hesitate to send me feedbacks.