Feature Wish List for Amazon Devices

From Echo devices, Fire tablets, Kindle to Audible: this is a laundry list of all the things I wish these devices do a better job of.

#AmazonEcho: I can't cast music to my household member's Echo

Problem: I want to be able to cast music from the Amazon Music app from my iPhone to my "household member"s echo device. Both devices are connected to the same wifi network & in close proximity. I still can't see the Echo device from the Amazon Music IOS app unless if they are both logged in from the same account.

Wish: Echo devices should be discoverable for casting audio/video from all Amazon apps (Audible, Kindle, Amazon Music) on all devices (IOS, Android, Fire, Windows, Web, etc.).