To me, Merlin is the shining example of what "a computer in everyone's pocket" could have been. Such an amazing app that connects so many people more intimately with the world around them.
I get occasional nudges to support their organization, but it's a clear and direct appeal, there are no dark patterns that I'm aware of.
Merlin is run by the Cornell Lab of Ornithology, so it should (hopefully!) remain good and free, unlike apps by private companies with a profit motive.
Yes! It's a rare example of an app that instead of trying to capture your attention into a virtual environment, helps you to direct it outwards into the real world.
The sound id in particular is just an amazing way to really extend what's possible for most people, and provides an on-ramp for people to identify more birds by ear alone (and in general to pay more attention to sound when in nature).
I might argue that Merlin — and especially eBird — lean a bit to heavily to the competitive "high scores" view of birding; given the impact of climate change on bird populations, encouraging people to travel the world and see as many species as possible is clearly problematic.
But that's a minor quibble, and Merlin remains one of the few apps I'd unconditionally recommend to anyone with the faintest chance they'd use it.
I get occasional nudges to support their organization, but it's a clear and direct appeal, there are no dark patterns that I'm aware of.