Uptime and SSL certificate monitoring doesn't have to be boring, confusing or expensive. Together with my buddy Mattias Geniar I'm currently building Oh Dear: a webapp to keep an eye on the health of your websites. Register here to try it out.
Joe Watkins, core PHP developer and author of (amongst many other things) ptrheads, is busy creating a PHP debugger written in PHP that you can just composer require.
This isn't just pipe dreams, the PHP code exists, it's alpha quality and largely untested ...There is much to do and you shouldn't design your workflow around this (or any alpha quality software) yet. What you should do is start reading code, testing, and opening pull requests...
You'll find the code of Joe's debugger in this repo on GitHub.