I bought my brother's iphone 3gs and it's not jailbroken and it's ios is just 4.1, id update it to 6.1.3 but i after reading people's comment saying it makes the phone sluggish, i refuse to do it, can anyone help me how can i just upgrade it to lower version that 6.1? i cant install my apps.please :(
См. статью: How to upgrage my iphone 3gs ios 4.1 to 5.1.1?