Surge for Mac - Advanced Web Debugging Proxy for Mac & iOS
BIND - BIND is by far the most widely used DNS software on the Internet.
Charles Proxy - HTTP proxy / HTTP monitor / Reverse Proxy
dnsmasq - Dnsmasq is a lightweight, easy to configure DNS forwarder and DHCP server.
HTTP Headers - HTTP Headers allows you to quickly see the HTTP header information for the current URL.
PowerDNS - PowerDNS offers open source DNS software, services, and support.