Apple is allegedly positioning iOS for something called AirTags, which are little Bluetooth trackers you can attach to items you might lose. You would then be able to find an item by activating the "Find My …" app on your phone if you should lose it at some point.
Bluetooth only has range of about 10-100 metres (depending upon the class of Bluetooth you have) but, if you've lost an item somewhere beyond that range, you'll be able to flag the item as 'lost' via your phone and then if another iOS user comes within range of your lost item, it will alert them with details about how to contact you.
Nobody really knows complete details about Apple's AirTags yet and much is based on rumour and supposition, but they are unlikely to be much different to existing products from other companies. There aren't many fancy things you can do with a tracker, although rumour suggests Apple's offering will be more accurate than some of the current products thanks to the ultra-wideband chips in Apple's latest iPhones. Apparently the AirTag will also have a chime you can activate to further help you locate a lost item.
It is thought Apple's AirTags will be rechargeable — some of the existing products are battery powered — and they will charge wirelessly in the same way an Apple Watch does. How long the charge lasts will be important because I can't imagine people will want to be charging these things too often. They are not things you'll want to have to think about on a daily or weekly basis.
Most existing products cost £20-£30 per tracker and I can't imagine AirTags will be any cheaper. It is after all Apple we're talking about here.
Bear in mind this is all speculation but if that speculation is to be believed we should see AirTags later this year.
Personally, I don't have too much use for this sort of thing. I suppose I might attach one to my keys or maybe a bag, but the truth is I'm a bit of a hermit and I don't go to too many places, so I have limited opportunity to lose anything in the outside world. I do lose things in the house from time-to-time but these are often rarely used things and it would be expensive to attach an AirTag to every item just in case.
My cutlery has a habit of randomly vanishing so maybe I should attach an AirTag to every knife, fork and spoon, although I've always thought that's down to an inter-dimensional fracture hereabouts and I'm not sure how AirTags would cope with that.