There were a lot of flash games I used to play and love but most for the best of me can't remember them anymore even if I tried to find them and get them running.
Also there was this game: "
Can you see me now?" by Blast Theory which was released back in 2003 as a sort of social/AR/Location based game experiment that they ran for a little while. Basically it was a version of tag/hide and seek where you (playing as a digital player on a 3D map) would have to hide/run away from others who would be in fact in the real world tracking you down on PDA's they had and trying to find you and catch you before the time ran out. The 3D map perspective was a generated map of a real space that spanned some streets and buildings and there would be multiple digital players but only a handful of actual "runners" on the ground chasing after you. This was long LONG before Niantic or anything that they would come out such as Pokemon GO. It was a fun as hell game that I enjoyed as a kid, and it was set up neat enough that you could hear the runners on the ground communicating with each other via 2 way radio which would be broadcasted on the player end side to hear in on whether or not they were talking about you and trying to find/approach you. It had way more engagement then it had any right to, especially for 2003.
Unfortunately the project stopped after some time probably due to it being a short term project/experiment and not something that was meant to stick around for long. I'd imagine keeping on Runners and other systems would have been expensive in the long run and they definitely were not doing this for any monetary gains.
Here is a small video about it.
I really loved this game as a kid and I wish they did something like this again. Even with the stuff that exists now there is still nothing like this that exists to such an intricate and well thought out experience.