the Fitbit mobile app
The SpyCam for Fitbit app sends an image from your phone or laptop camera to your smart watch.
On your Fitbit app, open the Settings page for the Spy Cam app and enter a channel name. Next start broadcasting using the link from the Spy Cam settings page either on your smart phone or laptop.
You can set the image refreshing rate on either your watch or the broadcast page. There are many other settings that can be customized.
Multiple watchfaces can subscribe to the same channel, and this app can be used to view any image if you have a webcam URL.
Regarding privacy, the latest broadcast image is stored in a temporary directory on a server. Anyone can type in any channel name, so others may be able to see images in your own channel.
Spy Cam costs $ 1.29 after the one-day trial period has ended.