sn0wbreeze

Despite being very popular, iOS devices are not exactly famous for the being highly flexible when it comes to customization options, such as changing the boot logo image or modify the root partition size. sn0wbreeze is a handy application that can help you tweak your device or upgrade its firmware.
The utility does not require any additional software to be installed on the host PC, as it does not even rely on iTunes to function smoothly. Additionally, you do not need to actually install it on your PC, as it can be run as soon as you extracted its files.
sn0wbreeze enables you to effortlessly download a firmware package, suitable for the device you own, be it iPhone, iPod, iPad or Apple TV, along with the iOS version you require. Alternatively, you can also load a previously downloaded IPSW file within sn0wbreeze.
Once the package has been correctly detected, you need to specify the processing mode you want to use: iFaith mode (suitable for creating custom firmware using iFaith or TinyUmbrella SHSH blobs), Simple mode (recommended for novices, as it automatically adds Cydia, afc2, SSh for Apple TV and other items to the device), Expert mode (it provides you with complete control over the customizations you want to apply) or Baseband Preservation Mode (should be used when you only want to preserve your iPhone’s baseband, without unlocking or jailbreaking it).
Due to sn0wbreeze, you get the chance to personalize the boot logo image, adjust the root partition size or enable battery percentage. You need to keep in mind that depending on the IPSW you loaded, some features within the Expert mode might be blocked, while some processing modes might even be missing (not all devices support the same tweaks).
All in all, sn0wbreeze can come in quite handy if you want to customize your Apple device, upgrade it to another iOS or simply download its suitable firmware.