I go to Burning Man every year and have learned a thing or two about surviving in extreme conditions. Here are my favorite of the survival guides and manuals for Android.
Army Survival Guide
This is the free version of the U.S. Army Survival Guide. It works offline and can be installed on the SD card. Chapters cover: Survival psychology; survival planning and kits; survival medicine; shelters; water and food procurement; firecraft; survival use of plants; poisonous plants; dangerous animals; field-expedient weapons tools, and equipment; desert, tropical, cold-weather, and sea survival; expedient water crossings; field-expedient direction finding; signaling techniques; contact with people; camouflage; and survival in man-made hazards. Illustrated. Easy to use. Awesome. Recommend.
US Marine Corps Close Combat
This app costs US$1.99 and has the entire U.S. Marine Corps Close Combat Training Manual – can be used offline. Chapters cover fundamentals of close combat; lethal and nonlethal weapons techniques; hand-held weapons; strikes; throws; chokes and holds; ground fighting; and nonlethal techniques. Searchable, illustrated, awesome. Recommend.
Field & Stream Online
This app has hunting, fishing, shootig, ad survival info from Field & Stream. All of the online content is available through this app – videos, photos, how-tos, articles, and more.
This app lets you quickly find the answers to diagnosing and dealing with sepsis. It has diagnosis, severity scoring systems, treatment, biomarkers, and references.
This app has news articles about survival, preparation, and reviews of gear that help with that. Not very sophisticated but good for keeping up with survival news.