While a Raspberry Pi is generally pretty cheap, an ESP8266 is even cheaper. And when I say cheaper, I'm talking about picking up one of these microcontrollers for $5 or even less.

A great example of this was the ESP8266 which was originally seen as a cheap WiFi ... The display of choice is the KeDei LCD 3.5″ module which was originally intended for use with a Raspberry Pi.

Or adding an ESP8266 to a Raspberry-pi, to get a wifi unable to stream anything with a useful bandwidth. Those devices are not meant to be friends. Anyway, do it, just because you can.

In its current form, the ZeroPhone is a Raspberry Pi Zero in a ‘PCB sandwich’ that has Wi-Fi (using an eSP8266), HDMI and audio outputs, a free full-sized USB host port and a micro-USB port ...