Israel’s Oriient (see here previously) uses slight changes in the earth’s magnetic field to enable users to find their way around inside buildings, the same way that Waze enables drivers to navigate outside. Put a list of products into the app, and it will map out the most efficient path through the store to buy those items
https://www.timesofisrael.com/spotlight/wheres-the-beef-israeli-startup-finally-delivers-indoor-gps/