I've considered making an app like that myself, but there are some inherent issues. Adding the data is tricky (scan barcodes for products? manual input? pictures?), and inventory management is a nightmare (how much flour did you use? What about cinnamon, etc, How do you add left-overs back into the inventory?).
It was my knee-jerk reaction to address the same problem. We ended up building a weekly(ish) plan and largely cook from scratch. Might be feasible if you just buy products and use the entire product every use, although that'd get expensive for other reasons. One caveat to the meal plan - leave flex to account for leftovers and unplanned stuff. Sucks to have food go bad because kids got sick and there was lower time for cooking, etc, etc.