The iStockNow site gives users live inventory updates for all major Apple products at every Apple Store around the world. While this information is available on Apple's website, there is no way to see it on a map view or check multiple stores at once – hence the helpfulness of iStockNow.
The website has been around for a while but is becoming useful again because of how hard it is to find AirPods. The site also shows stock of iPhones, MacBooks, Apple Watches – and the DJI Mavic, which joins AirPods as being the hardest gadget to find this holiday season.
For things like iPhones and MacBooks, users can filter by storage size, color, etc – which is also helpful when trying to find the exact device they want at a local store.