need tips on developing an iphone / android app

Looking for any advice on how to develop a recipe app for mobile devices that will cull data from a WP site. We are thinking about using the Query Multiple Taxonomies plugin on-site and also have a mobile app that will let people drill down through the ingredients to find recipes. The app should run off of the site content so that when the site is updated the recipes also appear in the app. The site will contain other (non-recipe) content as well, which will not appear in the app. I know there are several app builder plugins for WP. Any recommendations? Thanks.