Voltura Air
Turn your phone into a Windows remote, screen viewer and webcam
...Install the Windows host, scan its QR code, and open the controller in your browser. No mobile app-store installation or Voltura account is required. Direct LAN is the default, with optional Cloud relay for networks that block inbound connections. Device permissions stay under your control.
Free and open source under the MIT license. Standard, full, and portable Windows x64 packages are available.