To reset a device that has stopped responding to the instructions sent by the app, follow the steps below, in the order indicated. After each step, check to see if the issue has been resolved.
Sign out of the Hilo app by going to the Profile screen (last icon on the right at the bottom of the screen), by scrolling down and tapping on Log out. Sign in again using your email address and password and refresh the Devices screen by swiping your finger down from the top of the screen.
Disconnect the Ethernet cable (the one that looks like a telephone cable) from the gateway for about 10 seconds and then reconnect it. When the indicator light becomes solid green and stops flashing, refresh the Devices screen.