When it first hit store shelves, BB-8 by Sphero lacked support for voice commands through an Android device. That problem has now been remedied, with an update to the BB-8 app now making its way through the Google Play Store with support for voice interaction.
Getting started with voice commands is fairly straightforward. Open the Settings screen and switch Voice Commands to on. From there, you can interact with your little droid using your voice, such as the "go explore" command, which puts BB-8 into its patrol mode.
This latest update to the BB-8 app also fixes some communication bugs between phones and droids, and adds compatibility for several more Android phones and tablets. You can grab the update for the app from the Google Play Store.