Adam Katz@Thorium @wendynather there are a few. I'm using @GrapheneOS, for example. It's a security-hardened privacy-focused Android (AOSP) system, fully FOSS (if you refrain from installing the sandboxed Google Play, etc).
GNU social JP is a social network, courtesy of GNU social JP管理人. It runs on GNU social, version 2.0.2-dev, available under the GNU Affero General Public License.
All GNU social JP content and data are available under the Creative Commons Attribution 3.0 license.