Force Portrait Screen Rotation in MS Remote Desktop App
The Microsoft RDP android app didn't support portrait mode... but with your input on https://remotedesktop.uservoice.com/forums/272085-remote-desktop-for-android/suggestions/6851819-portrait-mode it finally got implemented:


  Our latest update to the app supports connecting in portrait mode. The
  remote session adapts to your device orientation dynamically. You will
  get the best experience using Windows 8.1 and newer.