[10] This iPhone was named "4s" where the "s" stood for Siri,[b] an intelligent personal assistant that was initially exclusive to the 4s and later included in future Apple products.

Reviewers noted Siri, the new camera, and processing speeds as significant advantages over the prior model.

[17] The 4s was officially discontinued on September 9, 2014, following the announcement of the iPhone 6, although production did continue for developing markets until February 17, 2016.

It was also Cook's first launch without Apple co-founder Steve Jobs, whose health was deteriorating, and he died the day after the announcement of the iPhone 4s.

Tim Carmody of Wired praised Cook for focusing on company achievements, calling him a "global business thinker" and a "taskmaster".

[22] Speculation about Apple's next generation smartphone, including various specifications and a predicted name "iPhone 5", had been widespread in the time preceding its debut.

[37] It can act as a hotspot, sharing its internet connection over WiFi, Bluetooth, or USB,[38] and also accesses the App Store, a digital application distribution platform for iOS developed and maintained by Apple.

The service allows users to browse and download applications from the iTunes Store that were developed with Xcode and the iOS SDK and were published through Apple.

The iPhone 4s can play music, movies, television shows, ebooks, audiobooks, and podcasts and can sort its media library by songs, artists, albums, videos, playlists, genres, composers, podcasts, audiobooks, and compilations.

Siri can be accessed by holding down the home button for a short amount of time (compared to using the regular function).

An impact of Siri, as shown by Apple video messages, is that it is much easier for people to use device functions while driving, exercising, or when they have their hands full.

Entered text is supported by predictive and suggestion software as well as a spell-checker, that includes many regional dialects such as Swiss spoken French.

[42] According to Apple the update contained 200 new features and tweaks, which included a new maps app (dubbed Apple Maps), Facebook integration, and Passbook, an application that allows users to store their coupons, boarding passes, and tickets digitally.

On December 22, 2015, Apple faced a class action lawsuit alleging that they had knowingly slowed down iPhone 4s devices with iOS 9.

On July 22, 2019, Apple released iOS 9.3.6 for the iPhone 4s to fix issues caused by the GPS week number rollover.

The iPhone 4s uses the Apple A5 system-on-chip (SoC), also found in the iPad Mini (1st generation), that incorporates an Imagination Technologies PowerVR SGX543 graphics processing unit (GPU).

This GPU features pixel, vertex, and geometry shader hardware supporting OpenGL ES 2.0.

The screen is the same as the prior generation iPhones; 3.5 inches (89 mm), 640×960 resolution (Apple's "retina" design).

[40] The camera on the iPhone 4s, also known as an iSight camera, can take 8-megapixel photographs (3,264 by 2,448 pixels) and record 1080p videos at up to 30 frames per second with upgraded quality [50] (30% better clarity, 26% better white balance, color accuracy) due to an additional lens, IR filter, a wider f/2.4 aperture, and Image signal processor (built-in A5).

The bottom of the device features a speaker output on the right and a microphone input on the left with the Apple proprietary 30-pin dock connector in the center.

[41] In addition to user inputs, the device also has several sensors that give the smartphone information about its orientation and external conditions.

Reviewers noted Siri, the new camera, and processing speeds as significant advantages over the prior model.

"[15] Joshua Topolsky of The Verge stated that "if this were to be a car, it would be a Mercedes" and that Siri is "probably one of the most novel applications Apple has ever produced.

Brian Chen of Wired said that "the fifth-generation iPhone's superb camera and speedy dual-core processor are classy additions.

[58] Echoing technology pundits, Reuters suggested that the lack of a more radical departure from the iPhone 4 could open new market opportunities for rivals.

[59] Analyst C. K. Lu of Gartner believed that Apple no longer had the leading edge and that the 4s would only sell due to brand loyalty, as fans had been expecting an iPhone 5 with a thinner profile, edge-to-edge screen, and stronger features.

Not only is it now pushing out games that simply eclipse the 3DS visually, but features like cloud saving and TV streaming support are really exciting for gamers.

"[47] The senior gaming analyst at Jon Peddie Research, Ted Pollak, believes the biggest improvement to gaming on the iPhone 4s is the voice control features, noting that "one of the features that Nintendogs players loved was the ability to talk to it.

"[63] In 2012, the iPhone 4s won the T3 "Work Gadget of the Year" award, beating RIM's Blackberry Bold 9900, rival Samsung's Galaxy Note amongst others.

"[2] The used smartphone market saw unprecedented rates of trade-ins in the weeks leading up to the 4s announcement, and after it, there was a drop in prices offered.