Is it possible, if we get cooperation from the owner(s) of the site and/or their development team.
As this would need modifications on both the client and server side.
However, I do think this is something we should not do right away, but later on, as we would not only have a lot of work for it, it would also require us to work with others a lot.
Which can slow things down dramatically, so it be best to use this later on, or use a system that allows users to subscribe to a site, after the site supports the application.
Then we can go ahead and make the application without having to wait for a site to finish their work, since it would be universal, and it would also make it easier to later have other sites be added.