I’ve been building a browser-first project called RelicBeam, and one feature I wanted was simple in theory:

Open a folder on one device and temporarily browse it from another device without installing anything.

That became Remote Files, part of RelicBeam’s Device Portal.

The host selects a folder, another device joins with a QR/code, the host approves the connection, and the second device can browse, preview and download files.

The folder itself is never uploaded to RelicBeam.