[tomsem]

It will probably be awhile before this shows up on Fire devices. Trying it out on my iPad.

I see that there's now a Setting to 'Stream only on Wi-Fi' option, which seems only to apply to Channels at present (wish they would enable streaming for audiobooks also). Channels stream by default, but you can download them (one segment at a time) for offline listening.

There are around a hundred channels.