You often want to identify different flora and fauna while hiking. Since I have my smartphone with me either way, I would like to have an app to do so.
Which apps tackle the described use-case and also do they work offline?
Google Lens is Google's technology for "searching what you see", including plants and animal. Since it relies on Google's service, doesn't work offline.
Identify plants and animals
Find out what plant is in your friend's apartment, or what kind of dog you saw in the park.
It's available on:
Based on my experience in identifying my dog, photos of insects, and flowers, it might not always be too accurate, though the suggested results with their visual representation sometimes helped.
Disclaimer: not affiliated with Google, just a happy user of it.