A lot of people probably already know this exists, but for those who don’t, there’s an awesome app that tells you what birds are around from their calls/songs. It’s called “Merlin”. You can also give it photos to ID. I usually leave it running in my pocket or hand while I walk around my local RSPB reserve.
It cannot be overstated how cool the audio ID function is. I would not have learned the difference between a red-tailed and red-shouldered hawk otherwise.