The Google Camera was added to Playstore earlier this year and in every update it used to get a lot of functionality. The Google Camera app has received Material Design in the very last update. Google has been updating all of its apps with the Material Design before the release of Android Lollipop.
Google has updated its Camera app with Android Lollipop compatibility. The app version got updated from 2.4.008 to 2.4.023 on the Google Playstore yesterday which adds the Android 5.0 compatibility along with updated Material Design. Google has also squashed few bugs from the app.
The other Google apps which has got the updated Material Design are Google Play Store, Google Play Music, Google Chrome, Google Play News Stand, Google Drive, Google Play Games, Google Play Movie & TV and Google Play Book.
The Android Lollipop update is about to hit the Nexus devices on November 3rd. We expect the other updates to get rolled out in the mean time.
You can download the Google Camera app from this link.