The scale is a standalone unit. The V4 trickler user interface is via an app loaded on an external device (smart phone/tablet). It is convenient, and lowers cost, but does expose the user to problems associated with Bluetooth connectivity and software operating systems interoperability. I wouldn’t be surprised to see a dedicated (non Bluetooth) interface offered in the near future.I may be living in a cave...you need a phone app to run a scale or trickler ??