The Echelon App is currently available on the Apple iOS App Store and the Android Google Play Store.

Software:
 

iOS devices 
Requires Apple iOS 15.0 or later, but the device needs the ability to update to the latest version of the APP

Other Reference: A helpful link to determine if your Apple iOS device is compatible: https://blakespot.com/ios_device_specifications_grid.html

Android Devices 

Requires Android 6.0 and newer. 
Please note: The Echelon Fit app will not work on Amazon Fire Tablets or any other devices that do not permit Google Play Store or App Store apps, eg Windows, Linux, Mac OS, etc