The menu button, which “hides” a bunch of functions in every Android application, was essentially scheduled for retirement since the release of Honeycomb. For persistent developers however, Google issued an official announcement, prompting them to no longer integrate the menu button in their applications. The goal is to completely replace it with the action bar, which was also first introduced in Honeycomb. This one however, will include a new discreet button, called action overflow, which reveals a series of icons for mostly-used functions like refresh, delete, etc. To find out more details, read the related post on Android Developers.