Despite being a retail exclusive at Sprint, the Essential PH-1 has arrived as an unlocked device. However, as mobile fans are unfortunately familiar with, certification with one particular network is always tricky. Tonight Essential announced that its flagship phone is compatible with the Verizon network, just a day after it went on sale in Sprint stores, so owners can drop a SIM in and go on all of the major US carriers. According to Andy Rubin, devices may need to reboot first, but that's it.