https://github.com/dscalzi/HeliosLauncher
Please give credit to the original author and provide a link to the original source. This is free software, please do at least this much.
For instructions on setting up Microsoft Authentication, see https://github.com/dscalzi/HeliosLauncher/blob/master/docs/MicrosoftAuth.md.
The best way to contact the developers is on Discord.