If these Tile bluetooth tell-your-phone where it last was things worked for Android, which they don’t, I would put one in my sunglasses case.
That said, they seem a bit pricey? $20/year/tracker?
I’d buy the stock if it were available, though.
(Wait a minute: the “use other people’s participation to track your lost stuff” aspect might be a real privacy nightmare once the government starts subpoenaing the records.)