Bought for my son who was trekking the Inca Trail to Machu Picchu. Three flights to there and back and he had the assurance that is bag was on the same plan as him.
He also loading the app on my phone and took the tracker in his pocket during the 4 day treck along the Inca trail up to Machu Picchu. When the app could send the tracker position, I could find him using Google Earth, pinpointing where he was and using bird eye or roadside when available, I could see what he was seeing and it was like walking along with him. The scenery was amazing.