I've been doing APK teardowns for a while now, and most of the time exciting updates end up being relatively boring under-the-hood, only rarely dropping really fascinating hints at future functionality. Today, I was pleasantly surprised, as the situation with YouTube 5.2.27 is exactly the opposite - the update itself couldn't be less boring, but the nugget we dig up inside will make a lot of you very happy.

Background audio

So, without further ado, I'm glad to report that background audio should be finally coming to a YouTube app near you, if all goes well during testing. This feature will let you start a video, exit the app, and switch to something else without the audio stream dying, which is incredibly useful when listening to podcasts or music videos, or just quickly checking an incoming text. Moreover, it should work with the screen off.

Based on my observations of users' comments with every app update, background audio is now one of, if not the most, requested Youtube for Android feature.

While the setting, UI, and the background service for background audio are currently hidden, we managed to reveal the setting long enough to pose for a screenshot and are currently working on a possible Xposed module to enable it on rooted devices. No promises, as this may be a tough task, though if you can help make it happen, you'd instantly become a hero in the eyes of many.

Observe:

Here are several more relevant strings from the APK:

<string name="background_dialog_cancel_bgol">Cancel</string>
<string name="background_dialog_learn_more_bgol">Learn more</string>
<string name="background_dialog_message_bgol">YouTube can now keep playing in the background!</string>
<string name="background_dialog_ok_bgol">OK</string>
<string name="background_dialog_title_bgol">Background</string>
<string name="background_dialog_turn_off_bgol">Turn off</string>

<string name="pref_background_audio_enabled_summary_bgol">Continue playing audio when the app is running in the background or the screen is switched off</string>
<string name="pref_background_audio_enabled_title_bgol">Background audio</string>

<string name="syncing_video_bgol">Syncing video...</string>
<string name="youtube_playing_in_the_background_bgol">YouTube playing in the background</string>

Raise your hand if you've been waiting for this as much as I have.

Bonus

As a bonus today, we have some messages YouTube will use when offline support is finally launched. All of these are new in 5.2.27, so you can imagine my disappointment when I couldn't find a single trace of them in the UI:

<string name="delete_from_offline_done">Video is removed from offline</string>
<string name="menu_save_to_offline">Add to Offline</string>
<string name="notification_progress_completed">Download Completed</string>
<string name="notification_progress_size">%1$d MB / %2$d MB</string>
<string name="notification_queue_title">YouTube Offline</string>
<string name="offline_adding_progress">Adding... %1$d%%</string>
<string name="remove_from_offline">Remove from Offline</string>
<string name="remove_offline_action">Remove</string>
<string name="remove_offline_video_confirmation">Remove from offline?</string>
<string name="save_to_offline_done">Video added to offline</string>
<string name="save_to_offline_error">Error adding video to offline.</string>
<string name="save_to_offline_start">Adding video to offline...</string>

<plurals name="notification_queue_text">
    <item quantity="other">%1$,d videos added to offline.</item>
    <item quantity="zero">No video added to offline.</item>
    <item quantity="one">1 video added to offline.</item>
    <item quantity="two">2 videos added to offline.</item>
    <item quantity="few">%1$,d videos added to offline.</item>
    <item quantity="many">%1$,d videos added to offline.</item>
</plurals>

Thanks again to @TheNewsHQ for the APK and Santiago Rosales for teardown help!