One of the smartphone of Apple is iPhone4s which was launched in the year 2011.
This phone was a very good and a though body. I personally have dropped the phone many time from my hand and it did not have any problem. The iPhone easily fits in any pocket giving not much trouble
The iPhone Currently is running on the latest version of iOS8.4. The company has also informed that iPhone 4s will get the update to the next iOS to come which is iOS 9
Seeing about the battery life iPhone does not touch the mark in its battery where in the user of 4S will have to keep charging or will have to keep an external source of battery backup due to which the phone tend to heat up a little bit.
It supports 3G where in downloads are fast and video call can be done with not much trouble(provided your network connection.)
Talking about the camera it has a 8MP primary camera where in very good like "I MEAN VERY GOOD" photos can taken. Overall this phone is good to use!