Is this app available anywhere besides Google Play? I want to put it on my Kindle!
Interesting question, and seeing i'm always intrigued by questions like this i went to do some research.
According to my first findings, the old kindles don't support it, but it seems the New Kindle Fire HD does support google play apps, or t least can connect to the google play store.
that link shows the supported devices, which doesn't contain Kindle (it does, but only for eBooks it seems)
if I were you, jut send a mail to google play store support and verify wether or not you can use apps on your Kindle.