Nextcloud -- you can share links to files you store on your own server.
If you don't have a persistent server and/or don't want to go to the trouble of hosting your own 'cloud', you could try 'Magic Wormhole' to share files as well.
For Windows, try one of these: https://duckduckgo.com/?q=windows+magic+wormhole+client&t=vivaldi&ia=web
On Android there's a client called 'Wormhole William' -- unsure of the iOS equivalents but I'm sure they exist.