They launched with an iPad - only
app, then
expanded to iPhone, the web, Android, Nook, and Kobo, and today they announced that they are making their entire digital
catalog, about 1,500 volumes right now, available for the Kindle, including Kindle Fire and Paperwhite, as well.
Alexa's other advantage over the Home platform is its ever -
expanding catalog of Skills (over 15,000), which are like
apps for voice - controlled speakers.