CloudFlareDDNS
Create your own DDNS service with CloudFlare.
The updateCloudFlare.php will allow you to update an existing DNS record in your CloudFlare account using the CloudFlare API and your API key.
Update the PHP file with your own details and host online. Call the file with a cron job every 5 minutes to regularly update your DDNS entry.
*/5 * * * * /home/user/updateCloudFlare.sh
Read more on my blog: https://scotthel.me/cfddns