If you have uninstalled a device and it still appears in Neviweb, you need to rescan the network. This operation will force a rebuilt of the network of connected devices.
In Neviweb, select the gateway in the All Devices screen.
Press the Rescan Network button at the bottom of your gateway’s settings page. A confirmation message will appear, press Rescan Network again.
Once the network is rebuilt, the uninstalled device will no longer appear in Neviweb.