A free app for Android, by Developed with Google.
WiFiNanScan is an application for measuring the distance between two smartphones using the Wi-Fi Aware protocol. It is designed as a research, demonstration, and testing tool for developers, vendors, universities, and more. It is possible to measure the distance with a precision of about 1 meter, with phones up to 15 meters apart.
WiFiNanScan enables the development of peer-to-peer ranging and data transfer, and find my phone and context-aware applications based on the Wi-Fi Aware/NAN API. It is a tool that is used to develop and test applications that use the Wi-Fi API.
You must have a phone that supports the Wi-Fi RTT protocol to use this application.