The marker has "anamendieta.club" text above with outstretched arms beneath. Print it out or try it from the computer screen.
The dropbox link for the marker: https://www.dropbox.com/s/pc0w60ai7s85vcy/marker.jpg?dl=0
Download the .apk from this link.
The next step is to drag it onto your Android device.
[Note: I have only installed from a computer to a device. I don't know how to download it onto a device and install directly but it can't be more complicated than this.]
The file should be in the folder "My Files".
Open the app on your Android device.
Point it at the marker.
It will look something like the image below.