When Song Sleuth brings up the list of possibilities you can either agree or disagree with it. If you aren't sure, you can listen to the preloaded calls to compare to your recording. You can even compare spectrograms of the prerecorded calls to the ones you captured. If the app brings up the incorrect identification, you can go into the full list of birds in the app to try and find it.
I played around with this app with sounds from the All About Birds site and with bird calls in my local patch. Let me tell ya, trying to find singing birds in a Minnesota winter is not that easy. I had mixed results with the app. I would say about 60% of the time it nailed the id, especially if I trimmed down the recording and try to filter out wind. But 40% of the time the bird I was trying to id wasn't on the list. Part of it was disagreement with the app about what birds occur in Minnesota in winter. We have an influx of tufted titmice in the Twin Cities this year and the app didn't think they should be here so never considered the bird a possibility. I had to go in and manually include in the list of possible birds.
But I do love that this app gets you into a habit of visualizing bird sounds on a spectrogram. I think that visual clues are very handy for someone just starting out and you'll be surprised to see the distinct vocal patterns birds can have, even with an accent. I also love that this app lets you record calls and even if it doesn't get the correct id right away, you have something you can take home and compare with bird sounds online. I played with this on an iPhone 7 and was able to pick up bird and squirrel sounds from far away. Ideally, you want to be as close as possible to get the call, but considering the size of the microphone on an iPhone it does a decent job.
I also think that over time the app will improve as more people start to use it. To get an idea of how it works, check out the video on how to use the app. It's not a perfect app, but if you are struggling to learn your bird calls, I do think it's worthwhile to download.