From observation so far, SocketWeaver works cross-platform:
Android, iOS, Windows, MacOS, and Linux.
Except… Web-based…
For someone who works for mobile, I personally think the pricing is attractive (without CCU limit).
Speaking of experience, I am actually having a look at the sample projects now. Will feedback more afterwards.
By the way, when you mention ‘Mirror’ is free, does it mean it is free to have it published in Steam?
Let say I need to enable multiplayer game in android (google play store), technically the hosting will cost, is it?