Earlier this year, Google integrated bubble notifications into the core Android 11 experience. The new feature allows designated chat apps to open free-floating windows that can be minimized to movable bubbles. The latest app to add support for this is Skype, and you can already try it out for yourself.
Microsoft has rolled out this new feature with version 8.67 of Skype. You can either update the app via the Google Play Store or download it from APK Mirror. I tested the feature on a Pixel 3a running Android 11 and it works just fine, as you can see from the screenshots below.
Tap the 'bubbles' icon visible in the bottom-right of the notification to enable chat bubbles.
For the feature to work, you'll need to first enable it on your phone by heading to Settings > Apps and notifications > Notifications > Bubbles. Once enabled, Skype notifications in the tray should show an icon to launch them as a bubble (see above). Tapping on the icon will launch chat bubbles, and all your new Skype conversations should appear as floating icons.
Apart from introducing chat bubbles, the new update also adds support for the Android 11 features Priority Conversations and Conversation Space.