There are 2 spots where you'll see a green light on the Ava - on the top and the underside.
Top green light (solid): your Ava is charged.
Underside green light (solid): should switch on upon contact with your skin and remain on throughout the night until you wake up the next morning.
Top blue light (blinking): Ava's Bluetooth is activated and "findable" by other nearby Bluetooth devices.
Top blue light (solid): Bluetooth connection between Ava and your phone has been established and syncing is in progress.
Top red light (blinking): Ava's battery is low and needs to be charged OR Ava's memory is full and needs to be synced to the app.
Top red light (solid): Ava is plugged in and in charging mode.