Sites that claim they find a songs key

[John_E]

Finding the KEY?

Hi Friends I’ve been away for sometime, but i haven’t stopped plucking. however, i feel like i’ve hit a wall. I’m curious if anyone knows of an app or easy look and tell to find the key of a song? I suppose it likely comes with practise, and i did see a youtube video of two floating around about using the A string and plucking your way down the string to see what harmonizes the best, but i find myself second guessing? i assume that this might come from a high end theory practise too, but i’m…