The 2011 iPhone 4 only had a 5-megapixel camera, compared with the 8-megapixel shooter of the Droid X. But it was one of the first phones to sport a backside-illuminated sensor (the other being the HTC Evo 4G).
In 2012, Nokia turned heads with the announcement of its 808 Pureview, which packed a whopping 41-megapixel camera. The phone ran on the clunky Symbian OS, but it took remarkably beautiful pictures.
Nokia's pact with Microsoft to use its Windows Phone operating system led many to hope the camera tech would be ported over to a Windows Phone, giving the struggling operating system something buzzworthy.
Where the megapixel counts were heading upwards, HTC decided to look backwards with the 2013 HTC One.
The phone featured a 4-megapixel camera, but its larger sensor used 2μm pixels for better low-light shots. The company used the same camera for the sequel, but was widely panned by consumers for the low resolution despite it taking pretty good images.
Where high-end phones were sporting new cool features, Asus took a different route with its midrange ZenFone 5. The phone had a 8-megapixel camera, but had software enhancements that let it take pictures in pitch dark environments by combining four pixels into one.
The process, known as pixel binning, wasn't new (the 41-megapixel Nokia phones used a similar method), but it gave this midrange phone something to shout about.
While the 2014 iPhone 6 Plus kept the 8-megapixel camera, Apple finally added optical image stabilization to the phone. There's a chance that Apple may introduce a larger megapixel camera in its next phone, due later this year.
While Apple kept to the 8-megapixel count, the 2014 Samsung Galaxy S5 kicked it up a notch with a 16-megapixel shooter. Despite the higher count, image quality didn't suffer and Samsung's flagship phone showed just how good its camera had become.