You can make yourspot tracker positions avaiable online, so you can always someone else to keep an eye on them too if you really want. IMO spot trackers are an overkill and you need to be able to see the sky ie outdoors use for a spot to work well.

Just a heads up that any device that uses GPS for its location sensing is prone to canyoning in urban locations with narrow streets and tall buildings. Newer devices less so but might pay to test accuracy of any solution you go for before using it in anger.