Hi @robotpie, you already got good answers specific to the smartphone zoom lens, but one line in your original post caught my attention:
I’m not so ready to buy a full camera set yet as I am more interested in recording observations rather than photography
My 2 cents since I was recently in the same situation. I used smartphone for iNat for ease of use, timestamp, GPS, iNat app, etc. Like you, I’m more interested in the observation than the artistic/photography side. This was fine for plants, big animals, many insects. However even with a lens attachment it was horrible for birds, small fast-moving insects, or really anything more than a short distance away.
I recently needed a new camera (for other uses than iNat). I did some research and decided on a ‘bridge’ camera. After some searching I got the Nikon P900. Point-and-shoot style photography with huge zoom and built in GPS. Essentially a modern smartphone sensor attached to a compact telescope.
Incredible difference. The 89x zoom factor means I don’t even bring binocs. Image quality is not as good as SLR, but zoom surpasses anything they offer and quality is good enough for ID. So much more intuitive and fun to use than smartphone+lens. I observe things I wouldn’t without it (recently parasites on the back of a flying fox high up in a tree). You get natural shots without scaring animals by trying to get close. Output JPEGs play well with iNat - time and GPS stamps picked up accurately. Honestly I would never go back to smartphone. This is just so much more… fun.
While it’s not exactly cheap, the price is going down all the time and is still half the price of the new iphone… check my observations if interested in examples of what it can do in complete amateur hands.