Stupidly, even trying to sign in with Google on the Nest "works with"
link doesn't work- because Google didn't update to their own standards.
Gives "error: 400 redirect_uri_mismatch" with further detail "you can't
sign into this app because it doesn'...
You're completely correct, after this long they should be only one app
and none of the Nest being separate app. Google needs to get so many
things fixed.
I'm having the same issue. According to some help info I saw online from
Google, the home app should be giving us the option that says "add
existing device" however it does not give us that option in our app.