iPhone

The original iPhone did away with a physical keyboard entirely, relying on a 3.5-inch, 320×480 touchscreen at 163ppi, and a body with an aluminium back and just four buttons plus a switch. It launched with 4GB and 8GB storage options, with a 16GB variant added several months later as the range matured.

The rear camera was a single 2MP sensor with geotagging and no front camera at all. Inside sat a Samsung ARM chip deliberately underclocked from 620MHz to 412MHz to preserve battery life, paired with a PowerVR MBX Lite GPU and 128MB of eDRAM. There was no GPS (the Maps app relied on Wi-Fi and cell-tower positioning instead), no MMS, no copy and paste, and no way to install third-party software of any kind. 

Because of that last point, several publications at the time argued it wasn't really a smartphone by the conventional definition; that changed only with the iPhone 3G and the App Store a year later. 

Software updates gradually filled in some of the gaps over its three supported OS versions, though it never received the full iPhone OS 3 feature set.

Connectivity was limited to quad-band GSM with GPRS and EDGE, no 3G, which reviewers flagged as its biggest shortcoming alongside its AT&T exclusivity in the US.