This is a simple module that displays a bunch of information inside the 3D View window, in a slightly configurable manner.
This idea (and much of the original code) was blatantly stolen from from the Speedflow (https://blendermarket.com/products/speedflow), whose features I've found I don't really need -- but I loved the overlays! The original Speedflow code has been hacked almost beyond recognizability, but you can still see bits of the original if you look.
This addon should definitely be considered beta quality at best, but it works well for me! I will gladly fix any problems found if they are reported (via Github issue, ideally, but I'll also take email, text message, smoke signals...).
If you get no text in the 3D viewport, something is probably crashing -- check the Blender console, and if it's dumping out a bunch of errors, open an issue with the error text. I'll probably make it better about catching its own errors in the future.
I hope someone finds this addon useful!