I know this is not what you asked but I would also considering not replacing all social medias at all. Just get rid of those you feel are not generally good for you and just replace that time with something actually fulfilling. Perhaps this advice isn’t for you but I am at least much happier when I don’t use too many social media services. So just wanted to throw this idea out there.

I like how it works on some browsers where it asks you which search engine you would like to use when you open the browser for the first time.