Unity3D Standalone 'Player'

Hi

I need to create a single generic build(player) for Unity3D projects that can run separate projects as an extension of the player/build. Suppose we have one Unity3d 'player' APK which can download resources of other projects at runtime on the backend and can further run it as an extension rather than a new application, such that there is no need to create a separate application for separate functionality. Say, I have a player application that can run application related to my organisation and only through that application a user can download (from the organisation's website) & use separate products. However, the 'player' application serves as a portal/middleware which can add a separate layer of encryption and exclusivity to it. I am looking to create PLAYER builds for different platforms - Android, Windows, iOS and Web browser (if possible). Example: VLC player serves as a media player that can play various kinds of video file. Similarly, I need a player that can run separate Unity projects for the specified platform by using project module uploaded on the server.

Thanks in Advance !