Hey team! Your idea reminds me of a case study featured in Switch by Chip and Dan Heath. While studying a Vietnamese community that suffered from malnutrition, the researchers found a few "bright spots"-- young children who were healthy. Rather than launching an educational campaign against bad habits, they were able to help hundreds of communities by leveraging a solution that came from their own community and made sense for their context. When considering how to help Hispanic communities eat healthier, there are some important questions to be asking: What is already going on that's working? Who is best positioned to lead/educate? Any sustainable solution has to suit the palate of its intended community, so this is a time to look to your experts-- your "bright spots," and let them lead. This article gives background on the Vietnamese case study: http://www.fastcompany.com/1514493/switch-dont-solve-problems-copy-success
When working technology into your idea, it'd be great to learn about who prepares the food and how they use smartphones. A Mexican-American friend shared with me that his mother didn't trust an app he had downloaded for her, but was immediately won over when she realized the app was released by Telemundo. In another instance, he taught her to take a citizenship quiz (which she did only reluctantly), and found both parents competing to get the higher score late into the evening. If you find that the matriarchs of the family are responsible for food purchase and preparation (this friend also shared several anecdotes of the kids feeding themselves while the parents were busy working), then these women's preferences and habits should be worked into your app. They may prefer a familiar name or need some coaxing to get started, but I think a smartphone app could be a good choice.
While sharing low-cost ingredients can help families cut costs, another way to help is to connect families to the best deals in terms of groceries. The Daily Table in Dorchester, MA sells dried goods, produce, and prepared food at a fraction of the cost (I got 6 bananas, 2 cans of tuna, 2 yogurts, and soup for $4.75). The Daily Table is putting products nearing their sell-by date to good use by preparing food that would otherwise be wasted and making healthy groceries more affordable. In this case, the issue may not be the availability of inexpensive groceries, but rather the knowledge of where and when to find them. This is an opportunity to leverage technology to help connect the consumer to the right goods. GasBuddy is a website and app which shares price information about gas stations in your immediate area and is kept up to date by the users themselves. Perhaps a smartphone app for groceries could work similarly, showing the best deals on groceries in your immediate area and connecting the dots between goods and consumer.
Best of luck, I'm excited to see how your idea evolves!