Google just released a new app that will let your friends know you’re up for hanging out. The Who’s Down app is currently invite only, which Google does a lot with its newer apps and services. If you do have an invite, what you can do is have access to a quick toggle switch that lets your friends know you are “down” to do a specific activity. And then that app lets you chat with your friends from within the app. You can download the app for free both on Android and iOS but again, if you don’t have an invite to use it, you won’t be able to.
Source: 9to5Google | Download: Google Play Store (Free) + Apple App Store (Free)