I had a Mastodon account on mastodon.technology from a while back (April 2017 my account says — looking for an alternative to Twitter in late 2016 sounds right). Unfortunately the instance is shutting down. I looked about for a new one tonight and a lot of them are already full, waitlist only. Which lead me into self-hosting, but the managed instance service I found, masto.host is also temporarily unavailable.
Seems like a lot of people looking for a Twitter replacement real quick. Might do some more reading this weekend on the Digital Ocean 1-click install option.