An app/website-neutral platform for open sourced social media

I have seen a lot of open source social media platforms like Mastodon, Diaspora, etc. which seem great, but then you realize you cannot connect with your friend who's on a different platform.<br><br>This gives me an idea for an app/website where anyone can create an account, and then link multiple open source social media platforms to their account and have a unified home feed kind of thing on our website, or app. We can also include features like followers, reply, DMs, etc. Kind of like real instagram, facebook and twitter but they can be a lot of work so this is a neutral platform if open sourced social media platforms want to connect with others without having to create everything from scratch. There can be multiple account types like Post, DM, Follow, Reply, etc.