The name of the device says it all: USB cable tester.
It will test what kind of USB cable it is by checking which signals on the connectors are inter-connected by the cable.
This helps identifying if a cable can transmit data, just deliver power, or if a USB-C cable can be used as HDMI cable.
STATUS: this project is still it its prototype phase. The prototype works, and is released, but lacks the Power Delivery feature. The final product is currently in design.
More details about the hardware are available here.
No binaries are released yet since this is still in the prototype phase. The source files are available in this git (keep in mind the usb_cable_tester branch).