Factbird supports analog sensor inputs.
Go to Devices in the Administration page and find the device you wish to set up an analog sensor on. Add a new sensor, or use an existing one if already in use.
2.1 - Find your sensor in the sensor overview by searching for it.
2.2 - Open up the sensor settings
In the “Basic information” tab choose “Measurement” from the drop down menu.
Go to the “Sensor setup” tab