There are things out there like the Works With Home Assistant badging program for things that work with #hass but we also want to know what doesn't work so we don't waste time and money on them.
If you've run across a IOT device that doesn't work with Home Assistant, or works poorly with it (like requiring a cloud service to control a device on your home LAN), please submit it to https://github.com/unixorn/internet-of-trash so I can add it to the list.
Thanks!