I have long wanted a home NTP server based on GPS (and now other similar systems like GLONASS) time reception. Unfortunately, most people who try to build one commercially want to put an OCXO in it, make it rack mountable, and target a $3000 price tag.
I would like to see one with a form factor and price more comparable to Startech’s network print server.
It would need: a small CPU, a GPS receiver with PPS output, an ethernet connection, and software to tie it all together. I would recommend against WIFI: I think the delay would be excessive, and there should be no need. This should be able to handle at least 1000 requests per seconds (as opposed to 100,000/second).
The device might, if desired, also make GPS data directly available, but this is of lower value for a device designed to be at a fixed site. The device also might support PTP and other mechanisms for publishing time (like the “daytime” and “time” protocols, and even an HTTP server). These are just differences in the firmware.
At this point, many people wanting such a device take a Raspberry PI and a GPS module and wire them together. This is only useful to the hobbyist market. 
I want a consumer grade version.