Play Books just hit version 4 yesterday, but on the surface it looks like very little has changed. There are a couple of relatively small tweaks here and there, but it wouldn’t appear to deserve a big version jump. However, this is the version that will launch audiobook support. A teardown shows that there’s a ton of new functionality hiding below the surface and it’s all just waiting for Google to flip the switch.
Play Books v4 prepares to launch audiobooks with support for casting and Android Auto [APK Teardown] was written by the awesome team at Android Police.