What is Pokémon GO Plus and how does it work?

Pokémon GO Plus + Troubleshooting Information – Pokémon Support

How to Connect Pokemon GO Plus + to Pokemon GO & Pokemon Sleep

Just like 'Pokémon Go,' the game's $35 Plus wearable needs some work

MODIFIED Pokémon GO Plus + Ultra and Great Ball Autocatcher with On/Off Switch

Pokémon GO Plus Keeps Revealing New Features It Wasn't Supposed To Have

Does this work for a pokeball+ or only the Go+? : r/pokemongo

Pokemon Go Plus review: This monster-catching button makes you less of a Pokemon zombie - CNET

The go plus plus won't work : r/TheSilphRoad

Official Bluetooth Devices — Pokémon GO Help Center

Pokemon GO Plus + - Official Introduction Video