@chaosmonkey To some extent it depends on how much work you want to do, and how much flexibility you want to provide. I'm not familiar with existing run-your-own DNS UIs, though I am sure they exist.
If you just want something simple and you have the technical expertise you can potentially build it into your own web site or app, and either use a third party DNS provider's API or talk to your own DNS server(s) on the back-end.
3/n