One installer (.exe), with the .NET 8 runtime bundled in - nothing else to install. Installs to %LocalAppData%\Roster by default; no admin rights required.
The installer is not Authenticode-signed. Every release publishes a SHA-256 hash in the release notes so you can verify the bits before installing.
From PowerShell:
Get-FileHash Roster-Setup-1.2.3.exe -Algorithm SHA256
Compare against the value in the GitHub release notes. If they match, the file is byte-for-byte what we published. If they don't, do not install, and please open an issue.
Roster updates itself from GitHub Releases. The auto-updater (Velopack) polls hourly. New release packages are Ed25519-signed by the maintainer; the app refuses anything whose signature doesn't verify against a key baked in at build time. Updates download in the background and apply on next launch.
To freeze on a known-good build while the substrate (Roblox client, Windows) is in flux, toggle Settings → Updates → Pinned.
Use each account through Roster or elsewhere, not both - Roblox rotates the cookie on every session, which can invalidate the copy in your vault.