[vortico]

If any application developers want to update the "Playing ..." status on Discord, I wrote a C++ implementation that interfaces with Discord's not-very-well-documented IPC API. https://gist.github.com/AndrewBelt/2b386003f949b79f73e9f21c6...

[judge2020]

If you were willing to create a new discord developer application (which can be any name) you could use https://discord.com/developers/docs/rich-presence/how-to which is well-documented.

[vortico]

I tried recently, but that documentation is insufficient to update a developer application's Activity status. I think they removed some vital information when they replaced it with GameSDK. Perhaps you will have better luck.

GameSDK is not an option for some applications, such as those wishing to include only open-source dependencies.