The RethinkDNS resolver is a modern approach to DNS management, aiming to enhance privacy and security in DNS queries. It can be deployed on various platforms including Cloudflare Workers, Deno Deploy, Fastly, and Fly.io, showcasing versatility and scalability. Users have compared it to Pi-hole, indicating a user-friendly setup and effective ad-blocking capabilities. There is also curiosity regarding the long-term viability of the Rethink DNS mobile app, which has not been updated in years, suggesting a need for clarity about the project's status and future updates.