We are also changing how remote playback works for streaming personal media (that is, playback when not on the same local network as the server). The reality is that we need more resources to continue putting forth the best personal media experience, and as a result, we will no longer offer remote playback as a free feature. This—alongside the new Plex Pass pricing—will help provide those resources. This change will apply to the future release of our new Plex experience for mobile and other platforms.
As in, symfonium.app? If so, seems questionable, given its proprietary nature and unavailability outside the play store. Although, the feature set is interesting.
Edit: yeeeah, no
From their FAQ:
licences checks requires a call to the verification server from time to time