The Garden Gnome Package Viewer for desktops is built using Electron. The app uses Chromium to open and display packages created by Pano2VR or Object2VR in a browser similar to Chrome.
The Desktop Package Viewer checks for new app versions on Garden Gnome's server from time to time but does not send any data. However, if the packaged tour requires external content like Google Maps, then this will need to fetch the map tiles from Google's servers.