Kaidan’s source code can be found at invent.kde.org.
Nightly builds for Windows are available as a standalone binary.
Kaidan is available as AppImage and Flatpak:
We provide nightly builds for macOS.
Alternatively, you can get the latest nightly builds from here.
Very experimental nightly builds (based on the KDE Frameworks master branch) are available. Please note that they are not signed with a proper key, and updating the app is only possible by re-installing it.