MyTag uses Bluetooth to "see" if it is close to your phone.
Each MyTag has a high quality, European bluetooth low energy chip built in. This connects with your phone using the MyTag Finder App whenever your phone is in range (within 30 metres or so of the MyTag Classic, or within 70 metres of the MyTag Sport). (Range measured outdoors - indoors the range is shorter due to walls, interference etc).
You can manage up to 16 MyTags at the same time from your iOS device, or up to 6 from your Android Device.
Each MyTag keeps monitoring its connection with your phone - if it gets disconnected (because you go too far away) then it can sound an alert on your phone and on the MyTag itself.
At any time you lose your MyTag - just press the button on the MyTag Finder App to sound the MyTag alert. If its not in range the App will show you where it disconnected so you can see if its near you or not.
And if you happen to lose your phone, in the house, your car or your bag for example - just press the button on your MyTag, and your phone will ring, flash and vibrate so that you can find it easily EVEN if the phone is on "silent".
MyTag Finder has lots of settings so that you can customise how each MyTag behaves. For example you may want your keys to tell you they have been left behind, but not your daughters pencil case.
You can set different alert tones on your phone for each MyTag. So you instantly know if you left your keys or one of your other valuable items behind. You can also select different alert tones on your MyTags, so you can tell the difference between your keys and wallet when they alert.
On iOS phones you can even set a Quiet Zone. MyTag Finder detects your home or work WIFI network, and can disable disconnection notifications on one or more of your MyTags when your phone is connected to that WIFI Network. So if you usually leave your keys at your desk when you go to a meeting elsewhere within your office or workplace, the phone and keys won't alert you unnecessarily. However if you leave the office without your keys you will get the familiar alert that you left your keys behind.