Right now, it seems that peoples are shy to share their apps. We have a list on the wiki of what we have found + users contributions: https://github.com/kivy/kivy/wiki/List-of-Kivy-Projects
But i'm sure there is more. Like this one: https://play.google.com/store/apps/details?id=com.nrtech.nrt... - Kivy is not referenced anywhere, but it's based on it.