Check if Your iPhone is Tethered, Unlockable with F0recast

For those who are new to iPhone jailbreaking, it is not uncommon you will have the following questions in your mind: Can my iPhone 3GS be unlocked? What tool should I use to unlock my iPhone? blacksn0w or ultrasn0w? What’s the bootloader version of my iPhone? How can I know if my iPhone is tethered…