Not very useful at all
There are maybe two minutes worth of random canary songs recorded with varying quality. I doubt the author even has a license to use the sounds. No options whatsoever. You get a button for each sound, the sound plays, and thats it. I feel its a big waste of 99 cents, and it probably shouldnt even be in the app store.
Hacktually about
Canary Bird 's - Nature's Own Paradise - Soundboard