The GUI releases are in the 'gui' folder.
For Windows and macOS they're easy to find and use, just get the .exe or .dmg files respectively.
For Linux if you're using a package manager like apt in Ubuntu, there's no way to get older version of packages.
You could get the files from the above URL and manually unpack them and run from there.
Hope this helps, have a nice day!
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Luca Longinotti (llongi) Head of Embedded Platforms iniVation AG - https://inivation.com/ Zurich, Switzerland Office: +41 44 500 32 14