The Amazon Fire Phone's tricks are pretty sophisticated, even if they're never really put to good use. And its innards are complicated to match, according to a teardown by iFixit. But damned if they aren't pretty to look at.
The four front-facing IR cameras that track your face are pretty deeply buried in phone's front screen. That in combination with the tangle of cables and glue that don't particularly like to be detached from each other make for a phone that's really hard to repair. So don't crack that fancy face-tracking screen. [iFixit]