Looking for a google maps checkbox event or somethig like that

I’m still trying to name the problem I’m having :) I’d like people to walk around town and check in at some locations via an app or website. It is supposed to be a city game for tourists. “Check a few of our points of interest and come back to us to verify and you’ll get a small reward :)” I'd like the app to verify that the person was in the places that we have on our map. I was googling for some kind of checkboxes or something like that on google maps but couldn't find anything. Meaby My thinking is bad and I’m looking at it wrong…

Any ideas of how to get started with such a project?

Regards