I have had a Kindle for almost 6 years, along with a second Kindle and an app on my phone. I had a different question but this one popped up right after it. I've read all of the above comments and noticed that most of the devices listed are Apple iPhones or iPads. I have an Android smart phone (specifically a Motorola Droid turbo 2)and have never had a problem with a download or sync. Is it possible that the problem is with compatibility with apple products? (Both my Kindles are on Wi-Fi.)