You can find all the created events and their IDs at poap.gallery.
Winners can sign a message with their address at this site. Organizers can verify the signature here.
The main difference is that people don't have to sign up for participate in the raffles. This has some disadvantages, like that raffles results aren't stored anywhere, but it's perfect for quick hassle free raffles.
Events with a supply of +5000 poaps are not supported due to POAP API limitations.