Just created a brand new video on doing a fresh install of Retropie 4.1 on the Raspberry Pi, upgrading it to the latest version and installing RetroPie Manager for the easiest way to transfer roms to a RetroPie install, Via a Web interface.
No BS, no dribble. Straight to the point and step by step. Not asking for anything, I just want to share this awesome feature with everyone I can as Rom transfers were a nightmare!
This will work with any OS (Windows, MacOS or Linux) as the program, Etcher, is multi platform. It even write compressed images/isos.
For those that don't want to watch the video, it's in the experimental packages section if you want to go hunting