Ask HN: How do you use/would like to use location in your product?

I would like to know how are you using location data in your product. What new features you would like to build using the location information of your users? What are the challenges in building location aware features?

Context: We are building a platform for dynamic location. Developers can use the platform to get real time tracking, distance traveled, dynamic alerts, nearest-N drivers etc. I would like to know what other features developers want to build with location and what are the challenges in this space.