Google lens does a pretty good job of identifying plants, along with everything else. I use it a lot in our garden and a majority of the time it correctly identifies.
There is really very little need for 3rd party apps on this. I've yet to stump lens on any Fauna or Flora in my neck of the woods. I suspect it is location aware, which gives it a pretty big edge in filtering out duplicates.
Interesting, I can't use Lens. Installed it, but it just says "Thank you for updating. Lens will be available soon"
My success rate with Google Lens is about 80-90%, sometimes doing additional research to confirm between similar results.
With a couple different dedicated apps I had zero success.