I highly recommend Cook Smarts (https://www.cooksmarts.com/) for meal planning. There are a ton of recipes, lots of nutritional information, and the ability to select different dietary need versions of each recipe (vegetarian, paleo, gluten free), and number of servings. You plan your menu from the meals featured each week, with the preferred dietary version and number of servings, or swap out the featured meals with any of the archived meals. It will generate your grocery list, taking into account your selections (it usually does a good job if there are shared ingredients across the meals - at worst, it will list an ingredient multiple times). You can check off the ingredients you already have from the list easily, and it gives you the ability to email a link to the shopping list, so you can access it easily when you're out shopping and check them off. And, if you're an iPhone user, the app just became available: https://apps.apple.com/us/app/cook-smarts/id6717616148 . I've found that I don't really need an app (I'm an Android user) because the site works pretty well on mobile devices. It costs $90 a year, which I find well worth the solution to my "what am I going to make" dilemma I used to have constantly. And there are occasional sales, especially for gift subscriptions.