PinballMap.com is a great site which is open source and has an API for interacting with it so people can develop apps for Android and iPhone, iPad, Apple Watch, and Pebble Watch (see http://pinballmap.com/apps).
The PinballMap database seems to be maintained much more accurately and up to date than the Pinside Pin Map. It does so, I believe, through the use of administrators for regions and crowdsourcing by people using the web/apps. The disadvantage is that for places to play with no region administration I think there may not be a capability of documenting the locations. Additionally, it is very USA based. However, for the places with admins it seems to be much better than pinside's map.
So... wondering if there would be a way to make Pinside's Pin Map better (by it pulling data from Pinball Map using the API)... and if that could be reciprocated (such that when new data is added to Pinside's Pin Map it gets pushed to Pinball Map via API as well (but only for geographies with admins).
Note: A year ago someone started a similar request (but not in the feature forum) and it go little traction and no official response that I could tell (see https://pinside.com/pinball/forum/topic/pinside-pin-map-and-pinballmapcom-can-they-work-together#post-1070892).
So... primarily just bumping this, adding a bit of detail, and putting it in the Feature Request Forum with the hopes of getting an official response.