I haven't explored those apps much, but rather left them installed for if I ever need the information. I also have 'Medical Wikipedia', 'Sky Map', 'PlantNet', and 'Merlin', but I don't think I'd find much use with those in a survival situation. I would need to learn other skills first.
Not to hijack your post, but if anyone knows of other cool offline reference apps, that would be useful in a survival situation, it would be cool to know!
I own this one, as well as Dartnell's The Knowledge: How to Rebuild Our World from Scratch because I am a massive tech history nerd. (I'd love the idea of being able to survive a collapse but I'm too self-aware of my insufficient physical fitness for that, lol.)
Also for those who've not heard of the BBC series Connections, it's AWESOME. More useful for entertainment than as a reference, but the first episode literally explores the question "what would a single human have to do to survive if modern life suddenly became unavailable?" Here are all the episodes on Archive.org.
Download Wikipedia and put it on a USB drive. Then buy a portable solar panel so you can charge some electronic device to view the wiki. There's a lot of farming, gathering, hunting, etc knowledge on Wikipedia.
The text only download is way smaller than the media download, but the media may be worth it for identifying plants.
Also, having some information in your head will definitely help. I'm not an expert but I try to brush up on random relevant topics when I get some time.
If you don't already, a good thing to own is a road atlas of your country.
I also have been wanting an astronomical almanac that would have info like sunrise/sunset times (got that idea from I Am Legend), and various other sky stuff data I don't know how to use for timekeeping and navigation but would like to learn :] My lack of expertise (ok, maybe also motivation) has prevented me from finding one.
There used to be agricultural almanacs also, with recommended planting dates. I looked into the extant USA ones (Old Farmer's and Farmer's) but they seem to have devolved into something more like annual rustic-themed magazines with barely any useful info... :[