Record video from the running (> Xcode 8.2) simulator and convert it to gif

xcrecord

#!/bin/sh
output=$1
tmp_file=$(mktemp)

xcrun simctl io booted recordVideo "$tmp_file"

ffmpeg -i "$tmp_file" -pix_fmt rgb24 -r 10 -f gif - \
  | gifsicle --optimize=3 > "$output"

rm -r "$tmp_file"