Every BlizzNux Launcher release is announced on blizznux.com, and every release thread collects whether that version works for people.
Release posts
When a new version is published on GitHub, a post appears in Updates under the BlizzNux Launcher tag, usually within half an hour. It carries the full release notes, download links for the AppImage, deb and rpm, and a link to the release on GitHub.
Only finished releases are announced. Drafts and pre-releases are not. New versions are released as soon as a fix or feature is ready.
Does this version work?
Each release thread keeps one running reply: "BlizzNux Launcher vX works, confirmed by N people". It counts every install on that version that got Battle.net started or a game running with sharing turned on. A game that ran with issues still counts, because those issues belong to the game, not the launcher.
Updating
The launcher looks for a new version each time it starts and shows an update button in the bottom bar when there is one. The AppImage updates itself: it downloads the new version, checks its signature, replaces the file and restarts. With the deb or rpm the button opens the release page; download the new package and install it over the old one. The source code, every release and the issue tracker are on GitHub at github.com/BlizzNux/launcher.