[Implemented] Playlist settings in Dash, Plexamp, Mobile App

[aubrey.wodonga]

@ianwilt

the only way to edit a playlist’s cover photo, name, and description is through the web app

@ianwilt

unable to edit it from within the app

This is no longer the case. Plexamp can now be used to both create and edit playlists, and as of v4.9.0 it can also upload custom posters.

@ianwilt

custom playlist cover photos do not appear in the Plex mobile app

I just tested on Android mobile, and I believe this is also no longer the case