so there's some app called WooPlus that bills itself as a plus-size friendly dating app. don't waste your time with that, I don't think I've talked to a single human there, the app seems buggy af.
as far as the rest of them, I don't know if there's any app that is specifically not fatphobic, but maybe what I've done could work for you? In addition to having a couple full body photos, my profile specifically says "BBW" like in the first sentence of my 'about' section (even tho I don't really like that term - it's just generally wildly recognizable).