Snapchat released the update saying on their blog:

Now you can see exactly where your Snapchat friends are hanging out and what they are doing there if they have shared it as a story. The new feature is now available today to all iOS and Android Snapchat users across the globe. You can also see their location on a map. Snapchat’s latest feature lets you share your location with your Snapchat friends. Snapchat’s new Snap Maps will tell you exactly where your friends are. Some worry about the 'stalker factor,' particularly for Snapchat's younger users who might not fully grasp the implications of a technology that constantly broadcasts their location.If you’re in awe of your cool friends Snapchat stories and want to be part of the action, you can be. But for plenty of people, the new feature is just plain creepy. Obviously, Snapchat sees Snap Map as a fun and convenient way to connect with friends. It’s sort of like Apple’s Find My Friends and Facebook’s Live Location feature-only, you know, on Snapchat. Others can zoom in and find exactly where you are, down to the street address. Snap Map tracks your current location and places your Bitmoji avatar on a map like a pin. This week, though, Snapchat unveiled a feature that leverages your location data in a whole new way, and it’s got a lot of people freaked out. Sure, the app uses your whereabouts to help marketers sell you stuff, but what social media behemoth doesn't? What, you thought everyone saw that “Greetings from the Brooklyn Bridge” filter? Until recently, Snapchat didn’t do much with your location data beyond serving up geofilters and pushing location-specific stories. Snapchat has always known exactly where you are.

How to get to snap map