Update: The feature should be live for everyone. To get it, go to Google Keep on the web. You should see this message.
Once you share your first note, the feature will fire up inside the Android app as well.
You don't need the latest version of Keep for this to work, but we're including the latest APK at the bottom of this post regardless.
Google will soon give Keep users the ability to share their notes with friends and family members. How soon? It says the feature will start coming to Android devices today through the Play Store. It may even be a server-side change, one that doesn't require an app update and is already hitting Android devices (but here's the latest update just in case). The functionality should be available in the web version and through the Chrome Web Store to everyone right away.
There isn't much to Keep, and that's most of its beauty. It only takes seconds to jot down ideas or get a list going. Now friends or couples can get their thoughts going together.
Google is also bringing to Android a feature that recently appeared in the online version of Keep, the ability to search by color.
For many people, being able to collaborate in Keep is all they need to put competing note-taking and shopping list-making apps to bed. Similar to Docs, multiple users can work on a document at the same time and watch as the others makes changes. The service is available to anyone with a Google account, and its color-based organization takes little in the way of explanation to understand. So as soon as this feature hits more devices, don't be surprised if it turns into even more people's go-to notepad.
The APK is signed by Google and upgrades your existing app. The cryptographic signature guarantees that the file is safe to install and was not tampered with in any way. Rather than wait for Google to push this download to your devices, which can take days, download and install it just like any other APK.
File name: com.google.android.keep-3.0.03-3003-minAPI14.apk
Version: 3.0.03 (3003) (Android 4.0+)
Source: Official Android blog