The app can't connect the plug to my Wi-Fi

Try these in order

1. Make sure your router broadcasts a 2.4 GHz Wi-Fi signal. The plug supports Wi-Fi 802.11 b/g/n.
2. Keep your phone within 10 feet of the plug while you set it up.
3. Put the plug back in setup mode (hold the ON/OFF button for 20 seconds) and add it again in the app.