Firstly make sure you install Amazon Echo App on your device.
- In the Echo Application, tap on the menu bar.
- Select Skills & Games, search Nexus Home and tap on Nexus Home.
- Click on Enable Skill and link your Nexus Home account by entering your Nexus Home account credentials.
- Select the desired Hub from the list.
- In order to discover the devices added to your Nexus Home account by Amazon Echo, just say Discover Devices.
- To view the discovered devices, tap on Devices icon and select All Devices.
Note: Every time you add a new device to the Nexus Home app, make sure you follow the above process.