I've written a plugin for the Netatmo Welcome camera.
Before installing the plug-in you must obtain Netatmo ‘Client ID’ and ‘Client Secret’ keys by registering at dev.netatmo.com. Accept the Terms and Conditions but don’t tick the ‘Netatmo Enterprise’ box. You will also need the email address and password which you used when setting up your Welcome camera.
Once you've entered these details into the plugin config page the plugin will obtain authorisation from Netatmo and fetch presence data. For each face in your Netatmo database an Indigo variable will be created in a folder called Netatmo and set to 'Home" or 'Away'. These variables can then be used to trigger actions in the usual way. The plugin polls Netatmo every 30 seconds, or less frequently if you prefer; this is configurable. Netatmo API has a web hook facility which would seem to obviate the need for polling, but I have no idea yet how (or if) this would work with Indigo.
Please note that the plugin does not currently fetch video or snapshots and is unlikely do so in the future. The Netatmo registration and authorisation requirements for live video are much more onerous (for privacy reasons I assume).
Here's the download page:
https://www.indigodomo.com/library/400/Alan