I definitely think this idea has potential. I was an early player of Niantic’s (creator of Pokemon Go) location based game Ingress. I find the active and real world experience present in Ingress and Pokemon Go fascinating and valuable. Your Idea of using this ability to increase student engagement and learning is fantastic. In terms of a company I think it is smart that your app will allow teachers to create their content and attach them to geological locations. This would make popular local learning destinations repeatable as possibly new media has been attached and new lessons are present.
I like others who have comment would worry about the security of the students information while using the app, however that could be said of any device use by students. Even if this app was merely used within a school it would be great with students at recess and lunch accessing information in the hallways.