I use Tiles and have always been able to verify that my bags are onboard the aircraft (the range is a bit longer than Apple tags) and found there are sufficient users (as can be used by both Android and iPhones) that can also be tracked through the airport and whilst in touristy areas.
You can use them without a subscription but the subscription (AU$48.99/year) provides more options and peace of mind (including free replacement of any tile damaged during subscription period).
