AirTags
Suprised these havn’t been around for years, looks like they will be here soon.
Being brought to market by Apple means they should be seamless and will passively make their way in to peoples every day lives.

“AirTags, essentially Apple’s Tile competitor, were already known to be in the works. Based on details and assets found in Apple’s iOS code, AirTags are believed to be small tracking tiles with Bluetooth connectivity that can be used to find lost items — just like Tile.
The difference is that Apple’s AirTags will benefit from deeper integration with iOS, including within its “Find My” app. There, the tags will show up in a new “Items” tab allowing you to keep track of items that tend to get lost or stolen — like your keys, wallet or even your bike.”
