“FilePizza isn’t the only application like this. There’s p2pfileshare.com and sharedrop.io, to name a couple. FilePizza stands out because of the simplicity—just share a file and copy the URL—and because it has a unique URL. These links only work as long as the computer is on and the browser window offering the file is open. Without a cloud service, it’s on your device to share the file with whoever might download it. Close the tab, and the file is gone.”
What is good about this app (as the article also says, not the only one that does this) is there is no uploading of your file to any remote service, and once you close the browser, the access to the file is gone. The best part is just having to remember the domain name and that is really all — no accounts, no login, no installations, no complications.
See https://lifehacker.com/tech/file-pizza-sends-file-without-using-cloud-storage