Valve might soon be releasing their own version of Steam Spy.
Link - https://www.engadget.com/2018/06/29/valves-steam-spy-replacement-game-stats/
Link - https://www.engadget.com/2018/06/29/valves-steam-spy-replacement-game-stats/
It looks as though Valve has something up its sleeve to replace Steam Spy. According to PC Games N, Jan-Peter Ewert, the head of business development at Valve, was asked about Steam Spy at a game industry conference. Ewert responded that developers needed "something better than Steam Spy," and that Valve was working on it.
“Our general approach has always been to provide open APIs so that when we don’t offer the amount of tools that we should, the community can step in. We are very much working on new tools and new ways of getting data out of Steam, and we hope that data can be more accurate and more useful than what Steam Spy previously offered you.”