Anybody familiar with this? It's at my LHBS.
https://www.grapeandgranary.com/thermostat-uni-stat-iia-digital-controller.html
That only has on output. Is that all you need? The ones I use have 2, one for cooling and one for heating.
Since I mainly do lagers, and the room temp where the fridge is never really goes below about 65°F, I've never needed heat yet. I suppose most ale fermentations would still be doable under those conditions.
EDIT Looked into a bunch of options, and realize I don't have any reason to change anything. Some of the controllers won't handle the power draw of my full size fridge. Moreover, I seem to keep the ferment temperature within a narrower margin than some of them allow (no swing at all!) All I have to do is check the temperature a couple times a day. My system may be old fashioned, but it's dialed in, highly effective, and paid for. I like it.
(But if I had it to do over, freezer and a two stage is how I'd go. I'd probably still control ambient because liquid changes temperature more slowly. Hope that helps OP.)
EDIT Well I've upgraded; thanks, guys, for the inspiration. Did more research, decided on the basic 2 stage Inkbird (non programmable) and a Fermwrap taped to the back wall of the fridge. I will continue to control ambient while monitoring the temperature in the thermowell independently, and I will still serve as the intelligent control system. A minor adjustment to my longstanding system (just adding a heat source) but now I should be good for year-round ales and reliable winter D-rests on lagers.