Really great, but a listening issue – Do Re Mi Voice Training Review

My chorus class is rolling out with iPads next week and after only using this app for 10 minutes, I already see myself using this it a lot. My goal is to have each of the students sing all of of the notes in a specific locked octave. Since it's recorded visually, I can have the students show me proof that they were able all to do it (especially the students who have trouble matching pitch). The only problem I've noticed so far is that notes below E3 are registering in the upper octave. It's only "hearing" the overtones in my voice. I was singing D3 and D4 back and forth and all of the notes registered as D4 only.
Review by Vocalcoach125 on Do Re Mi Voice Training.