4. Sanyo Zio
Introduced in March 2010, the Zio was Sanyo's first Android phone. The smartphone was sold by Sprint and shipped with Android 1.6, later upgraded to Android 2.2. The phone came with Sprint's "ID packs," which enabled users to choose among collections of themed apps, ringtones, wallpaper and widgets. The phone had a 3.5-inch screen, 512 MB of storage, a microSD slot for up to 32 GB of external storage and a 600 MHz Qualcomm ARM11 processor.