Add similar services

README.md

@@ -14,3 +14,12 @@ An identity for developers on the web.
 - Add your subdomain under `subdomains.json` file.
 - Run `npm install` and `npm run sort` to sort the keys alphabetically.
 - Send Pull Request.
+
+### Similar Services
+- [is-a.dev](https://github.com/is-a-dev/register)
+- [is-a-good.dev](https://github.com/is-a-good-dev/register)
+- [thedev.id](https://github.com/fransallen/thedev.id)
+- [is-not-a.dev & localplayer.dev](https://github.com/open-domains/register)
+- [cluster.ws & wip.la](https://github.com/Olivr/free-domain)
+- [is-really.cool](https://github.com/is-really-cool/register)
+- [js.org](https://github.com/js-org/js.org) (*JavaScript projects only*)