New version doesn’t work on old device

This app has been a great resource for my son — freeing him from the old, unwieldy dedicated devices that he used to use. We found a great solution with Proloquo2Go and an iMainGo portable speaker. Unfortunately, the newer iPod Touch doesn’t fit into the iMainGo — and the “update” for Proloquo2Go won’t load on an older iPod. I’ve tried to reload, but I can’t get the old version of the program back. Please — either fix the update, or re-release an older version, so we can continue to use your product.

FrustratedFather2 about Proloquo2Go AAC, v3.0.5