iPhone customers on AT&T and Verizon have already been able to manage their accounts using the myAT&T and My Verizon Mobile apps, respectively, and now Sprint customers can finally do the same. The Sprint Mobile Zone app is now available for free in the App Store and provides subscribers with account information, a Sprint store locator, and basic device info (mainly battery and data connections). If you're a Sprint customer reading this on your iPhone, click here for a direct download.