Electron File Manager
I wanted to have a file manager with multiple tabs because Windows didn't have one. I wanted to make use of the full suite of tools modern web development offered.
When I am doing file transfers, there are always multiple explorer windows open alongside many copy progress dialogs. I wanted to add tabs and then also make multiple parallel copy paste dialogs. (The copy paste thing is still not implemented)
Screenshots

Click to view

Click to view

Click to view