I recommend Waistline if you use Android. It’s on F-Droid.

The barcode scanner uses a community run database (Open Food Facts) for nutrition facts so you might find that you need to manually input items or correct outdated info more often than compared to the more popular My Fitness Pal. Obviously that gets easier once you build up a collection of your usual foods in the app.

Yeah, I think that is the case.

No, not that I have seen. The free version of ChatGPT still provides access to the GPT-3.5 model. I don’t think that is going anywhere.

The deprecated stuff seems to apply to the various older models that are available to developers that use the API.

I believe that is still only for paid API and ChatGPT Plus.