Anvil is a great tool for making sites accessible on the local machine and local network, but it does nothing to make your sites accessible from the Internet, especially if you're behind a NAT or a dynamic IP. Finch and the other mentioned services here do, so it's a bit like comparing apples to oranges.

EDIT: typo

Also sort of like xip.io

xip.io doesn't tunnel anything, it just creates convenient DNS records.