I was looking for an easy way to help not to forget my iPhone and this work very well. Not many false alert. And the best, its free for what I use it for. I get a notification on my watch if Im between 20-30 away from my phone. Of course if you leave your phone in a vault with thick walls, youll get a notification at 5-10 feet away, but any device your react like that. Ive read their Terms of Service and I couldnt fing any hidden phrase that would allow them to share personnal information to others. Any way, I havent shared my contacts list with the app, I never allow this for any apps anyway, and Ive turned of the Backup option too... But thats me... You can pay a monthly fee for more options, but the free version is enough for my needs. Good work... Oh! I almost forgot, the tech support is REALLY GOOD, fast and courteous.