You should now see a list of available devices that the RTL-SDR has heard in your area. This can take several minutes, if your pie has just been started, wait 5-10 minutes and you should see some devices show up. Click Back and then Settings again to see the latest list.
Click on the device you'd like to configure. No data is stored for the device until it is configured.
Be aware that not all devices report properly and there are problems with incorrect device decoding. There is a know problem specifically with "Acurite Rain Guage" that will show up multiple times and be incorrect.