Are there any apps to improve wifi priority sorting in macOS?
i use this one for quick and easy on the road access, WiFi Scanner.app

http://wifiscanner.com/wifiscanner.html

it's worked from osx 10.11 to 10.12.3, if you have an older version of OSX, check out KisMAC

if you want to dig deep into the packets for collisions, injections, penetration testing, etc, checkout Wireshark