Yes, the service works alongside your smartphone, using the InvisaWear app. You’ll need Android 9.0+ or iOS 11.0+ and connection to a cellular network or Wi-Fi to send an alert.The devices are bluetooth-enabled. So your phone needs to be nearby – within bluetooth range – but not necessarily on your person. You can download the app from the App Store (Apple iOS) or Google Play (Android). You then pair your SmartWear device(s) with your phone through the app.