Doesn’t work with recorders? – Note Rush: Music Reading Game Review

I tried to use this with a tenor recorder. It’s in the key if C. It asked me to play middle C. I did. Then it asked me to play a G below middle C. I don’t have one! I tried restarting the program and gave it the C above middle C as Middle C. It again asked for the G below middle C but when I played that note, no response. My wife loves this app for her piano studio. I may try again. perhaps I’m not getting something here.
Review by Fr. Mark L. on Note Rush: Music Reading Game.