You ‘log’ munzees with your smartphone running the munzee app. It records both the QR code & your location and checks with the munzee server (american I think) that you are in the exact location for that munzee. A recent addition is that this check can be ‘queued’ so you can scan & record the munzee and then ‘log’ it when you get back in reception.
Each munzee is worth points, sometimes you get double points, some munzees give varied amount of points etc. Also the person that owns the munzee gets points each time it is scanned by someone.
You can print a munzee and stick it where ever you want. No reviewers, no minimum distance, nothing.
I tried it for a while as in theory it seems like a good game, but I got bored with it quickly.