Just went to repeaterbook and found the offering less then steller. They list 25 repeaters TOTAL for the state of North Carolina, and 1 repeater in Raleigh. Trust me there are many more.
) lists 640 for NC. and I believe has the data you would need for an app. You might contact the owner of the site and see if you can work out a deal.
I use repeaterbook.com to find repeaters. It has a proximity search function, and other advanced search features. Their database is more up to date and comprehensive than the program I have for my iPhone. Perhaps they offer an API service for app developers.
73 de Jeff W6UX