There's also a button in the iPhone control center. No need to even unlock your phone, just swipe down from the top-right!

Sadly, that is not my experience with the app. I would equate the time my Shazam loads and is ready to listen as roughly the same amount of forever that it takes to launch the native camera app and being able to take a picture.

You can add it to Control Centre and it's seemingly instant, just starts listening as soon as you press the button.

I'm a massive fan of Shazam in Control Centre. It let me have space for another app on the home screen, and they also sync with the iOS app now too.

Only problem with that is that it doesn't save the results in your list of Shazam'd songs.

Try long pressing to see history.

interesting. i've never messed with these options.