Very Good, But Please Vary Timbres

This is a very useful app, but I find that I have more difficulty when I am comparing pitches sounded by two different instruments. For example, I am learning to play the violin. When I attempt to tune to the piano, my accuracy goes down. Comparing the piano to the bowed violin string adds some complexity.
Please add a variety of timbres so that users can compare pitches between instruments.

Waitlossgyrl about InTune – Tuning Practice, v3.0.1