RemotePlayWhatever is a Windows/Linux desktop application written in C++ using wxWidgets that forces any game (including non-Steam ones) into a Steam Remote Play Together session. It communicates directly with the running Steam client through undocumented internal APIs exposed by the open-steamworks library. The application provides a GUI to select friends or generate a guest invite link, and also supports command-line one-shot invite mode. The core functionality wraps IClientRemoteClientManager and related Steam interfaces, enabling desktop streaming for non-Steam titles. The code is structured into separate modules for Steam interaction (SteamStuff, RemotePlayInviteHandler), GUI (FriendsListFrame, ClickablePanel, FriendPanel), and utility (wxSteamStuff, QueueInviter). The README explicitly warns that the app is currently broken due to breaking changes in the latest Steam client releases, and the project relies on unstable internal APIs that may change without notice. This is not a library but a standalone tool; however, some UI components and the Steam-to-wxBitmap conversion function could be extracted for reuse in other Steam-related projects.