2017-06-17: Thinking of an app to reveal bad road conditions and vehicle behavior.
Point phone camera out front window to identify surroundings and other vehicles.
For safety, screen should, unfortunately, probably be blank to avoid driver distraction.
Otherwise colors and/or patterns could be drawn over the video to indicate the trouble.
Rewind-in-time feature records a slinding window of video, retaining only maybe 5 seconds.
If something exciting happens, yell "RECORD" to save those 5 seconds and continue recording.
The driver should comment on the situation to be played to others when they encounter the same.