Sadly, Kugelblitz is only available for Mac and is closed-source for now. And, of course, it's vibe-coded. He talks a little bit about his reasoning on his podcast (in German): https://logbuch-netzpolitik.de/lnp563-des-kaisers-neue-kleid...
Really can't stand him any more.
And yes, project is not even F/LOSS. 3D mouse recommended, this guy is aloft from the rest of human civilization.
There is also a Netflix Mini-series inspired by the case: https://en.wikipedia.org/wiki/The_Billion_Dollar_Code