A sampling of the activities:
Which Car Would You Buy- Presents sounds produced by cars and car parts and links these to purchasing decisions.
What's Making This Sound? and Sounds Like?- Have you listen to sounds or people's descriptions of a sound in order to guess what they are talking about (inferences!).
Eyes vs. Ears- talk about "listening with your eyes" while exploring how visual input helps us understand sounds .
Stop Me If You've Heard This One- demonstrates that you can't talk and listen at the same time! I have a lot of students that can benefit from that one...
That's where I heard it, and the age is right!
Ultimately, Sound Uncovered is probably best for older (upper elementary, MS/HS) and high-functioning students, but the interactives could be adapted for young students. Exploratorium, the interactive museum of science, art and perception in San Francisco, offers a similar open-ended app called Color Uncovered, which also looks to be a good context for eliciting language and description.
Common Core Connection:
CCSS.ELA-Literacy.SL.6.1d Review the key ideas expressed and demonstrate understanding of multiple perspectives through reflection and paraphrasing.