Twitter runs a single web application.

They also do make games.

Particles and waves aren’t actually separate as we were taught in school. They are in reality a third thing with properties of both.

As for detecting properties that’s a limit of our technology not the universe. In order to observe something we currently have to interact with it (e.g. bounce some light off it) It’s possible in the future we develop techniques that don’t require interaction, like reading the higgs boson field directly for example.