3.5 in. diagonally.
Yes, the iPhone 4 and 4s models are the same size so all cases and screen protectors will fit the same.
Same size as the iPhone 4's (9 cm aka. 3.5 inches)
No. If you want your phone to have a screen about 4 times the size, buy an iPad.
The iPhone 5 is 123.8 mm (4,87 in) high, 58.6 mm (2.31 in) wide and 7.6 mm (0.30 in) thick. The screen is 101.6 mm (4 in) across the diagonal
The iPhone SE has a 4-inch screen (3.48" by 1.96").
as about the size of a iPhone or a iPod
4.7 inches.
320 by 480 pixels
4.7 inches.
You can't but if you break you iPhone screen like I did, when you go to repair it they don't fix the screen they replace your iPhone and it will be jailbroken.
The iPhone 4S has the exact screen as the iPhone 4. (3-5 inch, 960 by 640 pixel "Retina Display")
No. The iPhone 5 is physically bigger than the iPhone 3GS.