Tiddlyhost.com is a hosting service for TiddlyWiki created by Simon Baird. Once you sign up and confirm your email you can create "sites", (i.e. TiddlyWikis), with support for online saving. Sites can be private or public, and you can optionally list them on the taggable and searchable Tiddlyhost Hub where they'll be discoverable by others.
Unlike TiddlySpot, Tiddlyhost is secure, open source, and has proper support for TiddlyWiki5. It also allows uploading existing TiddlyWiki files, supports TiddlyWikiClassic, and lets you claim ownership of your TiddlySpot sites. For more information see the FAQ and the About page.