Are you looking for an app to basically give a shopping list as well as generate recipes you can make per meal? I don’t know I have seen any.
I believe there are apps like my fitness pal that you can extrapolate recipes from websites (i think it will do shopping lists too), but I am not sure this fits what you are looking for.
A blog I enjoy reading (TheSpruceEats) recommended this as their best overall meal planning app (https://www.paprikaapp.com). Not sure if it is very complicated but sounds like what you are hoping for.
Otherwise it might be easier to hire a health coach or nutritionist for a couple months to go over meal planning catered to your needs and wants. Once you understand what foods you want to put together for a healthy meal, meal planning gets a lot easier.