WeatherUnderground.com: Weather Underground Weather Station iPad App Wunderstation no longer reports indoor temperature and humidity.
In June 2018, Weather Underground.com relaunched their Personal Weather Station hosting service and made a number of changes to their back and front end.
This is one of the features that broke after the new website was launched. If you are having an issue, you can reach Wunderground.com here:
AmbientWeather.net fully supports indoor and multiple channel sensors.
Here is a complete list of weather stations that work with AmbientWeather.net: