Format for saving game objects on IOS?

Hi!
I am making an IOS game in which users are able to walk through an interactive sound composition in the real world (using GPS), guided by a sonar system I have created. This part is all working perfectly but as part of the project, I want to make a tool for other composers by which they can use just the sonar part of my app (without my sound composition) as a composition/explorational method. The idea is that they use it to explore and make recordings of the location and then I provide instructions/a unity project so they can implement their own interactive composition.

To make this process more ergonomic I want to add a feature to the app where they can hit a button and type a note which will be stored along with the location of the note. The idea is that they can then move this file back to the computer, pull it into the unity editor of the project I provide, and create new game objects, in the right location, with their notes attached. These game objects will act as a way of geolocating features of the location/landscape.

I can imagine how to write the data to a json or XML but I am unsure if there is a way/format that can be understood by the editor?

Hope this makes sense (apologies for the nooby knowledge),
Thanks,
Ben