Searched for other threads mentioning Ingress, not many found so posting this here.

If you haven't heard about ingress, it's what PoGo is based upon. In 2014, this game was developed by Niantic Labs. Two factions would compete to control an area by linking up points in the game called portals. It was made with the goal of tracking user GPS data to improve Google's mapping API. It also had the feature of submitting portals for moderator approval, they would approve pieces of art and interesting points of architecture - that's why a lot of the portals (or stops and gyms) are churches. Later the same API from Ingress was taken from Ingress and applied to Pokemon GO.

If you like PoGo, I can highly recommend Ingress. Speaking as someone who's had the opportunity to play both there's objectively way more depth to Ingress, with active and thriving communities. If anyone would like an invite code please let me know via PM.