Rated 2 out of 5 stars
Sounds great, and handy for things I wanted to send, but in practice it randomly pops up with no user intervention *all* the time, sending all sorts of junk to my kindle before I disabled it. Tried changing the hotkeys, which didn't help at all. Until they fix the hair-trigger, it's really not very usable.
Ignoring the major problem, not taking over my active tab with the analysing window and offering an option to confirm before send every time would be nice improvements.