ContraCalls.appspot.com, is meant for dancers who either have difficulty hearing the caller or have difficulty remembering calls. It is free and works directly in all mobile phone browsers. A dancer records 8 calls in his/her own words during the walk-through and the recordings are played back repeatedly while dancing until playback is manually stopped. Youtube has a short video demoing ContraCalls at https://youtu.be/qqkQK7f-1_0 . 

You can try it out completely anonymously.

I would greatly appreciate learning any reaction you might have and especially for you to get the word out to dancers.

There may be other uses for ContraCalls?