The one app I’ve wanted to have when I visit someplace historical is an accurate map. But considering most places can’t even get a good (or at least spacially accurate) paper map, that’s not likely.
A lot depends on the type of historical place you’re talking about. If you’re talking about a museum, then I’d probably just like a QR code type of system which would allow me to get more information if I wanted to.
But if it’s a large site (like a battlefield, a large property or even a really full museum), then I’d like to see an interactive map with a suggested route. Far too often we find ourselves trying to figure out the best way to see a site, and we either miss information or find that we see stuff out of order and don’t get the best experience possible. So if there was an app which allowed you to either scan where you are or track you via gps then suggest the best route (or give options if you’ve got varied interests), that would be cool.
Just my opinions though…