Google Play offers downloads of TaxACT Express 2014 App for Android which enables you to prepare your federal and state taxes on your smartphone for free. Simply download the app, take a picture of your form W-2, and it will take you through a series of questions in regards to dependents, deductions, and income. It features refund tracking status, notification of processing, and extension filing.

Of note, it's also available for iPad with federal tax filing only.