Strypey#Nitter.net is to Titter as Invidio.us is to ThemTube. It provides a freely licensed (#AGPL) web app for their backend. You can login to your T account without using their nonfree Javascript, and manage it in ways that are a pain with the JS-free, legacy version of the T web UI.
Jonkman Microblog is a social network, courtesy of SOBAC Microcomputer Services. It runs on GNU social, version 1.2.0-beta5, available under the GNU Affero General Public License.
All Jonkman Microblog content and data are available under the Creative Commons Attribution 3.0 license.