sn0wbreeze is described as 'advanced jailbreaking tool that lets you build a custom IPSW ("iPhone software") file. It allows you to jailbreak your iPod or iPhone, so that it can run apps unapproved by Apple' and is an app in the System & Hardware category. There are six alternatives to sn0wbreeze for iPhone, iPad, Mac and Linux. The best alternative is checkra1n, which is free. Other great apps like sn0wbreeze are Animate (Free), Ultrasn0w (Free), Blacksn0w (Free) and BootNeuter (Free).
Blacksn0w unlocks your jailbroken iPhone, allowing it to be used with any GSM carrier (AT&T and TMobile in the U.S.) without a contract. It can be installed through blackra1n, the jailbreaking application by geohot.
unc0ver is a jailbreak, which means that you can have the freedom to do whatever you would like to do to your iOS device. Allowing you to change what you want and operate within your purview, unc0ver unlocks the true power of your iDevice.