Currently I have 17 apps published in Dusko Savic Google Play account. Six out of these 17 titles already live their electronic lives in Kindle store. Just as a point of reference here are the links so the you can compare the app versions against the Kindle versions:
I described here how I developed software to turn Kindle HTML files into apps, literally under one minute per conversion. In total, it takes under one hour from receiving a HTML file to have it published in the Play store, provided everything else is in place.
If you are interested in this kind of conversion, contact me here.