Mastodon
Self-hosted, globally interconnected microblogging community
... to the network's spread out and independent nature there are more moderators who you can approach for personal help, and communities with strict codes of conduct. You have 500 characters. You can adjust the thumbnails of your pictures with focal points. You can use custom emojis, hide things behind spoiler warnings and choose who sees a given post. Messed it up? You can delete & redraft for quick corrections.