Facebook's big-spending CEO presumably has a grand plan for Messenger, now that he's gone to such great lengths to own WhatsApp. For the time being though, his company is continuing to focus on subtle but useful changes to its homemade apps, with the Android version of Messenger just receiving an update to version 4.0. In line with the last week's iOS update, one of biggest new features is the ability to bunch your friends into groups and then pin these gatherings to a dedicated Groups tab, so you can quickly bombard the right people all at once. Unlike iOS, however, you can now also add a shortcut to any group or conversation directly from your Android home screen, letting you open up a floating chat head with a single tap, with no need to navigate through the app. That's the sort of convenience that reminds us why a dedicated Facebook phone was always so unnecessary.