Enjoy this moment, Galaxy S4 Active users—it will probably be the last update your aging phone ever sees. AT&T has announced the rollout of Lollipop on this device, and you should be able to grab it from the update menu now. The OTA will be somewhere in the neighborhood of 1GB.
Here's the official changelog.
- Android 5.0 Lollipop Highlights
- Songs, photos, apps, and even recent searches from one Android device can be immediately enjoyed across all of your Android devices.
- New User Interface look and feel, more fluid motions
- Priority mode to only allow certain notifications to get through
- Battery saving features and remaining time left to charge or deplete indicators
- Smart Lock to secure phone or tablet by pairing it with a trusted device like a wearable or car
- Most frequently used settings available with just two swipes down from the top screen
- Details at: http://www.android.com/versions/lollipop-5-0/
This is a build based on Android 5.0.1, but the UI and features will still closely follow the old way of doing things. Samsung doesn't like to completely change things up on a device, so your GS4 is still going to feel like a GS4, just a little prettier.