I wrote my own. I aimed for a different UX than most services. For my use case I have a few devices that I often share files between. So opening the tool on both devices was a bit annoying. Instead you select the file on the first device and you get a push notification on the other. Then the transfer is done over WebRTC (locally if possible). All communication is done end-to-end encrypted and over your browser's push service.

Hosted: https://filepush.kevincox.ca/

Source: https://gitlab.com/kevincox/filepush